Don't diagnose no-prototype callee-cleanup function definitions

We already have a warning on the call sites of code like this:
  void f() { }
  void g() { f(1, 2, 3); }
t.c:2:21: warning: too many arguments in call to 'f'

We can limit ourselves to diagnosing unprototyped forward declarations
of f to cut down on noise.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@221184 91177308-0d34-0410-b5e6-96231b3b80d8
Move the no-prototype calling conv check after decl merging

Now we don't warn on this code:
  void __stdcall f(void);
  void __stdcall f();

My previous commit regressed this functionality because I didn't update
the relevant test case which used a definition.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@221188 91177308-0d34-0410-b5e6-96231b3b80d8
Remove local handling of ASAN_OPTIONS and UBSAN_OPTIONS.

They are now forwarded by TestingConfig.py.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@221200 91177308-0d34-0410-b5e6-96231b3b80d8
Remove dead AST type argument to EmitFAbs

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@221205 91177308-0d34-0410-b5e6-96231b3b80d8
Lower __builtin_fabs* to @llvm.fabs.*

mingw64's headers implement fabs by calling __builtin_fabs, so using the
library call results in an infinite loop. If the backend legalizes
@llvm.fabs as a call to fabs later, things should work out, as the crt
provides a definition.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@221206 91177308-0d34-0410-b5e6-96231b3b80d8