Silencing C4141 warnings that were introduced en masse because __forceinline...

Silencing C4141 warnings that were introduced en masse because __forceinline cannot be combined with inline in MSVC without triggering this diagnostic. This is safe to disable because clang will catch instances of the issue with -Wduplicate-decl-specifier, so we are not losing diagnostic coverage.

llvm-svn: 247275