Clean up code in inifile.c
fix Issue 12689 - [CTFE] assigning via pointer from 'in' expression doesn't work
Merge pull request #3521 from 9rnsr/fix12689

Issue 12689 - [CTFE] assigning via pointer from 'in' expression doesn't work
Merge pull request #3354 from yebblies/inifile

[cleanup] Untangle the rat's nest in inifile.c
[Refactoring] Add StructDeclaration::fit to reuse it in other places
Supplement fix for DIP29 feature: Do not emit CastExp for const and unique conversions.
fix fix Issue 12681 - Rewrite rule prevents unique detection

Do rewriting in glue-layer.
fix CTFE interpreter