Pending test for SI-5459.
Renames normalize to normalizeModifiers.

Since we still have too many methods called normalize.
Changes many calls to normalize to dealiasWiden.

Calling normalize is very aggressive and is usually the wrong
thing. It is one of the leading contributors to non-determinism
in compiler outcomes (often of the form "I gave a debugging or
logging compiler option and it started/stopped working") and
should be used only in very specific circumstances.

Almost without exception, dealiasWiden is what you want; not
widen, not normalize. If possible I will remove normalize from
Type entirely, making it private to those areas of the compiler
which actually require it.
Expanded the comment on Type#normalize.

As suggested by reviewer.
Merge pull request #2013 from paulp/pr/normalize-less

Changes many calls from normalize to dealiasWiden.