Tweak implementation for allowing ObjC builtin type redefinitions.

- Replace string comparisons with pre-defined idents.
- Avoid calling isBuiltinObjCType() to avoid two checks. 
- Remove isBuiltinObjCType(), since it was only used in Sema::MergeTypeDefDecl().
- Have Sema::MergeTypeDefDecl() set the new type.

This is a moidified version of an patch by David Chisnall.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@55990 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed