Use 1 processes instead of 4 for phan

Running against mediawiki core phan needs around 1GB of memory
per process. >4GB is too excessive for a default setting. Instead
set the default to 1 process and add the ability for users to
select more processes on the command line.

Bug: T132636
Change-Id: I3d9fa462916fba519fe6d7f1916f881eefb6a942

tests/phan/bin/phan

@@ -31,9 +31,9 @@ php7.0 $PHAN \
 	--project-root-directory "$ROOT" \
 	--config-file "$ROOT/tests/phan/config.php" \
 	--output "$ROOT/tests/phan/issues/issues-${REV}" \
-	-j 4
+	"${@}"
 
-# Re-link the latest directory
+# Re-link the latest file
 rm -f "${ISSUES}/latest"
 ln -s "${RUN}" "${ISSUES}/latest"