Correctly track tags and enum members defined in the prototype of a function, and ensure they are properly scoped.

This fixes code such as:

enum e {x, y};
int f(enum {y, x} n) {
  return 0;
}

This finally fixes PR5464 and PR5477.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@151638 91177308-0d34-0410-b5e6-96231b3b80d8
15 files changed