it from several places. This merges the diagnostics, making them more
uniform and fewer in number. This also simplifies and cleans up the code.
Some highlights:
1. This removes a bunch of very-similar diagnostics.
2. This renames AssignmentCheckResult -> AssignConvertType
3. This merges PointerFromInt + IntFromPointer which were always treated the same.
4. This updates a bunch of test cases that have minor changes to the produced diagnostics.
llvm-svn: 45589
Chris Lattner