language: Move l10n-related classes from /cache to /language

* Make the code easier to own and maintain by being part of a topical
  area of expertise rather than a generic catch-all bucket.
  This also helps Gerrit team dashboards, [[mw:Git/Reviewers]]
  subscription patterns, more meaningful component prefix for
  [[mw:Commit_message_guidelines]].

* Prep for possible CODEOWNERS adoption.

* Prep for T166010 to give us better PSR-4 namespaces that we won't
  have to break/migrate again shortly after for the above.

Bug: T225756
Change-Id: I62c701d574d2a79365b1c5350f92bef47770e3ce

autoload.php

@@ -207,7 +207,7 @@ $wgAutoloadLocalClasses = [
 	'BotPassword' => __DIR__ . '/includes/user/BotPassword.php',
 	'BufferingStatsdDataFactory' => __DIR__ . '/includes/libs/stats/BufferingStatsdDataFactory.php',
 	'CLIParser' => __DIR__ . '/maintenance/parse.php',
-	'CacheDependency' => __DIR__ . '/includes/cache/dependency/CacheDependency.php',
+	'CacheDependency' => __DIR__ . '/includes/language/dependency/CacheDependency.php',
 	'CacheTime' => __DIR__ . '/includes/parser/CacheTime.php',
 	'CachedBagOStuff' => __DIR__ . '/includes/libs/objectcache/CachedBagOStuff.php',
 	'CachingSiteStore' => __DIR__ . '/includes/site/CachingSiteStore.php',
@@ -285,7 +285,7 @@ $wgAutoloadLocalClasses = [
 	'ConfigException' => __DIR__ . '/includes/config/ConfigException.php',
 	'ConfigFactory' => __DIR__ . '/includes/config/ConfigFactory.php',
 	'ConfiguredReadOnlyMode' => __DIR__ . '/includes/ConfiguredReadOnlyMode.php',
-	'ConstantDependency' => __DIR__ . '/includes/cache/dependency/ConstantDependency.php',
+	'ConstantDependency' => __DIR__ . '/includes/language/dependency/ConstantDependency.php',
 	'Content' => __DIR__ . '/includes/content/Content.php',
 	'ContentHandler' => __DIR__ . '/includes/content/ContentHandler.php',
 	'ContentModelChange' => __DIR__ . '/includes/content/ContentModelChange.php',
@@ -366,7 +366,7 @@ $wgAutoloadLocalClasses = [
 	'DeleteTag' => __DIR__ . '/maintenance/deleteTag.php',
 	'DeleteUserEmail' => __DIR__ . '/maintenance/deleteUserEmail.php',
 	'DeletedContribsPager' => __DIR__ . '/includes/specials/pagers/DeletedContribsPager.php',
-	'DependencyWrapper' => __DIR__ . '/includes/cache/dependency/DependencyWrapper.php',
+	'DependencyWrapper' => __DIR__ . '/includes/language/dependency/DependencyWrapper.php',
 	'DeprecatedGlobal' => __DIR__ . '/includes/DeprecatedGlobal.php',
 	'DeprecatedInterfaceFinder' => __DIR__ . '/maintenance/findDeprecated.php',
 	'DeprecationHelper' => __DIR__ . '/includes/debug/DeprecationHelper.php',
@@ -497,7 +497,7 @@ $wgAutoloadLocalClasses = [
 	'FileContentHandler' => __DIR__ . '/includes/content/FileContentHandler.php',
 	'FileContentsHasher' => __DIR__ . '/includes/utils/FileContentsHasher.php',
 	'FileDeleteForm' => __DIR__ . '/includes/FileDeleteForm.php',
-	'FileDependency' => __DIR__ . '/includes/cache/dependency/FileDependency.php',
+	'FileDependency' => __DIR__ . '/includes/language/dependency/FileDependency.php',
 	'FileOp' => __DIR__ . '/includes/libs/filebackend/fileop/FileOp.php',
 	'FileOpBatch' => __DIR__ . '/includes/libs/filebackend/FileOpBatch.php',
 	'FileOpPerfTest' => __DIR__ . '/maintenance/fileOpPerfTest.php',
@@ -553,7 +553,7 @@ $wgAutoloadLocalClasses = [
 	'GetReplicaServer' => __DIR__ . '/maintenance/getReplicaServer.php',
 	'GetTextMaint' => __DIR__ . '/maintenance/getText.php',
 	'GitInfo' => __DIR__ . '/includes/GitInfo.php',
-	'GlobalDependency' => __DIR__ . '/includes/cache/dependency/GlobalDependency.php',
+	'GlobalDependency' => __DIR__ . '/includes/language/dependency/GlobalDependency.php',
 	'GlobalVarConfig' => __DIR__ . '/includes/config/GlobalVarConfig.php',
 	'GrepPages' => __DIR__ . '/maintenance/grep.php',
 	'GuzzleHttpRequest' => __DIR__ . '/includes/http/GuzzleHttpRequest.php',
@@ -710,11 +710,11 @@ $wgAutoloadLocalClasses = [
 	'JsonContentHandler' => __DIR__ . '/includes/content/JsonContentHandler.php',
 	'KkConverter' => __DIR__ . '/includes/language/converters/KkConverter.php',
 	'KuConverter' => __DIR__ . '/includes/language/converters/KuConverter.php',
-	'LCStore' => __DIR__ . '/includes/cache/localisation/LCStore.php',
-	'LCStoreCDB' => __DIR__ . '/includes/cache/localisation/LCStoreCDB.php',
-	'LCStoreDB' => __DIR__ . '/includes/cache/localisation/LCStoreDB.php',
-	'LCStoreNull' => __DIR__ . '/includes/cache/localisation/LCStoreNull.php',
-	'LCStoreStaticArray' => __DIR__ . '/includes/cache/localisation/LCStoreStaticArray.php',
+	'LCStore' => __DIR__ . '/includes/language/LCStore.php',
+	'LCStoreCDB' => __DIR__ . '/includes/language/LCStoreCDB.php',
+	'LCStoreDB' => __DIR__ . '/includes/language/LCStoreDB.php',
+	'LCStoreNull' => __DIR__ . '/includes/language/LCStoreNull.php',
+	'LCStoreStaticArray' => __DIR__ . '/includes/language/LCStoreStaticArray.php',
 	'LangMemUsage' => __DIR__ . '/maintenance/language/langmemusage.php',
 	'Language' => __DIR__ . '/includes/language/Language.php',
 	'LanguageAr' => __DIR__ . '/includes/languages/LanguageAr.php',
@@ -775,8 +775,8 @@ $wgAutoloadLocalClasses = [
 	'LocalIdLookup' => __DIR__ . '/includes/user/CentralId/LocalIdLookup.php',
 	'LocalRepo' => __DIR__ . '/includes/filerepo/LocalRepo.php',
 	'LocalSettingsGenerator' => __DIR__ . '/includes/installer/LocalSettingsGenerator.php',
-	'LocalisationCache' => __DIR__ . '/includes/cache/localisation/LocalisationCache.php',
-	'LocalisationCacheBulkLoad' => __DIR__ . '/includes/cache/localisation/LocalisationCacheBulkLoad.php',
+	'LocalisationCache' => __DIR__ . '/includes/language/LocalisationCache.php',
+	'LocalisationCacheBulkLoad' => __DIR__ . '/includes/language/LocalisationCacheBulkLoad.php',
 	'LocalizedException' => __DIR__ . '/includes/exception/LocalizedException.php',
 	'LockManager' => __DIR__ . '/includes/libs/lockmanager/LockManager.php',
 	'LockManagerGroup' => __DIR__ . '/includes/filebackend/lockmanager/LockManagerGroup.php',
@@ -818,7 +818,7 @@ $wgAutoloadLocalClasses = [
 	'MagicWordArray' => __DIR__ . '/includes/MagicWordArray.php',
 	'MagicWordFactory' => __DIR__ . '/includes/MagicWordFactory.php',
 	'MailAddress' => __DIR__ . '/includes/mail/MailAddress.php',
-	'MainConfigDependency' => __DIR__ . '/includes/cache/dependency/MainConfigDependency.php',
+	'MainConfigDependency' => __DIR__ . '/includes/language/dependency/MainConfigDependency.php',
 	'MaintainableDBConnRef' => __DIR__ . '/includes/libs/rdbms/database/MaintainableDBConnRef.php',
 	'Maintenance' => __DIR__ . '/maintenance/includes/Maintenance.php',
 	'MakeTestEdits' => __DIR__ . '/maintenance/makeTestEdits.php',
@@ -844,6 +844,9 @@ $wgAutoloadLocalClasses = [
 	'MediaWikiSite' => __DIR__ . '/includes/site/MediaWikiSite.php',
 	'MediaWikiTitleCodec' => __DIR__ . '/includes/title/MediaWikiTitleCodec.php',
 	'MediaWikiVersionFetcher' => __DIR__ . '/includes/MediaWikiVersionFetcher.php',
+	'MediaWiki\\Cache\\Hook\\MessageCacheReplaceHook' => __DIR__ . '/includes/language/Hook/MessageCacheReplaceHook.php',
+	'MediaWiki\\Cache\\Hook\\MessageCache__getHook' => __DIR__ . '/includes/language/Hook/MessageCache__getHook.php',
+	'MediaWiki\\Cache\\Hook\\MessagesPreLoadHook' => __DIR__ . '/includes/language/Hook/MessagesPreLoadHook.php',
 	'MediaWiki\\Collation\\CollationFactory' => __DIR__ . '/includes/collation/CollationFactory.php',
 	'MediaWiki\\DAO\\WikiAwareEntity' => __DIR__ . '/includes/dao/WikiAwareEntity.php',
 	'MediaWiki\\DAO\\WikiAwareEntityTrait' => __DIR__ . '/includes/dao/WikiAwareEntityTrait.php',
@@ -928,8 +931,8 @@ $wgAutoloadLocalClasses = [
 	'MediaWiki\\Hook\\LinksUpdateHook' => __DIR__ . '/includes/deferred/Hook/LinksUpdateHook.php',
 	'MediaWiki\\Hook\\LocalFilePurgeThumbnailsHook' => __DIR__ . '/includes/filerepo/Hook/LocalFilePurgeThumbnailsHook.php',
 	'MediaWiki\\Hook\\LocalFile__getHistoryHook' => __DIR__ . '/includes/filerepo/Hook/LocalFile__getHistoryHook.php',
-	'MediaWiki\\Hook\\LocalisationCacheRecacheFallbackHook' => __DIR__ . '/includes/cache/localisation/Hook/LocalisationCacheRecacheFallbackHook.php',
-	'MediaWiki\\Hook\\LocalisationCacheRecacheHook' => __DIR__ . '/includes/cache/localisation/Hook/LocalisationCacheRecacheHook.php',
+	'MediaWiki\\Hook\\LocalisationCacheRecacheFallbackHook' => __DIR__ . '/includes/language/Hook/LocalisationCacheRecacheFallbackHook.php',
+	'MediaWiki\\Hook\\LocalisationCacheRecacheHook' => __DIR__ . '/includes/language/Hook/LocalisationCacheRecacheHook.php',
 	'MediaWiki\\Hook\\LogEventsListGetExtraInputsHook' => __DIR__ . '/includes/logging/Hook/LogEventsListGetExtraInputsHook.php',
 	'MediaWiki\\Hook\\LogEventsListLineEndingHook' => __DIR__ . '/includes/logging/Hook/LogEventsListLineEndingHook.php',
 	'MediaWiki\\Hook\\LogEventsListShowLogExtractHook' => __DIR__ . '/includes/logging/Hook/LogEventsListShowLogExtractHook.php',
@@ -1110,7 +1113,7 @@ $wgAutoloadLocalClasses = [
 	'MergeableUpdate' => __DIR__ . '/includes/deferred/MergeableUpdate.php',
 	'Message' => __DIR__ . '/includes/language/Message.php',
 	'MessageBlobStore' => __DIR__ . '/includes/ResourceLoader/MessageBlobStore.php',
-	'MessageCache' => __DIR__ . '/includes/cache/MessageCache.php',
+	'MessageCache' => __DIR__ . '/includes/language/MessageCache.php',
 	'MessageCacheUpdate' => __DIR__ . '/includes/deferred/MessageCacheUpdate.php',
 	'MessageContent' => __DIR__ . '/includes/content/MessageContent.php',
 	'MessageLocalizer' => __DIR__ . '/includes/language/MessageLocalizer.php',