This does not rename all the internal variables, functions, and types
whose names were based on the old syntax.
I think it adds new syntax support everywhere it's needed while
retaining enough of the old syntax support that early adopters will
see nice deprecation messages guiding them to the new syntax.
These are tests that fail in the next commit without this flag. This
does not add -verify-ignore-unrelated to all tests with -verify, only
the ones that would fail without it. This is NFC since this flag is
currently a no-op.
To correctly call designated super class initializers the designated
intializer (and not the allocator) is dynamically replaceable.
Convenience allocators are dynamically replaceable as before.
We weren't doing much validation when dynamically replacing storage
declarations, and has an assert() that should be an error. Clean up this
area a bit, dealing with simple ambiguities (i.e., there are two
properties or subscripts with different type signatures; pick the
matching one) and reporting an error when there is a true ambiguity.
Fixes rdar://problem/46737657.
