In looking at early flame graphs and XHGui profiles, I noticed
code paths like `decode -> decode@2 -> decode@3`, for example for
magic words arrays and special page names.
Rather than storing these as `[a, [a, [a, ..], [a, ..], [a, ..], .. ] ]`
store them instead as `[v, [ .. ]]`. This makes for smaller files,
but more important it further reduces runtime overhead.
Bug: T218207
Change-Id: I492e5d32106ba7fd1b22075cf026fee2e3d1944e
