Remove MSVC compat hack since the inline keyword was added in 2015

Our minimum MSVC toolchain requirement is greater than 2015, so we don't
need this conditional macro anymore.  New versions of MSVC apparently
have a header, xkeycheck.h, to check that keywords haven't been
redefined.

Fixes PR41144

llvm-svn: 356524

llvm/include/llvm-c/Target.h

@@ -22,10 +22,6 @@
 #include "llvm-c/Types.h"
 #include "llvm/Config/llvm-config.h"
 
-#if defined(_MSC_VER) && !defined(inline)
-#define inline __inline
-#endif
-
 #ifdef __cplusplus
 extern "C" {
 #endif