Move two Darwin-specific hacks into #ifdef __APPLE__. These were stat'ing
nonexistent Darwin-specific files on every module build.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@182331 91177308-0d34-0410-b5e6-96231b3b80d8
Revert r182331, these checks should be based on the target not the host.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@182333 91177308-0d34-0410-b5e6-96231b3b80d8
doc. parsing. HeaderDoc documentaton allows use of
@class command on an @interface declaration. Turn off
the warning for this case. // rdar://13927330


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@182334 91177308-0d34-0410-b5e6-96231b3b80d8