[Preprocessor] Add a macro for -fno-gnu-inline-asm

[bruno]

Summary

When building with -fno-gnu-inline-asm and -fmodules on Darwin, the compilation might fail if some of the implicit modules try to use gnu asm inline. For example, the issue happens when building _Builtin_intrinsics because of inline asm in cpuid.h

Add __CLANG_NO_GNU_INLINE_ASM macro when -fno-gnu-inline-asm is used and allow the user to ifdef asm inline's if desired.

[bruno]

Abandon in favor of https://reviews.llvm.org/D23905

lib/Frontend/InitPreprocessor.cpp

     Builder.defineMacro("__CLANG_CUDA_APPROX_TRANSCENDENTALS__");
   }
 
+  if (!LangOpts.GNUAsm)
+    Builder.defineMacro("__CLANG_NO_GNU_INLINE_ASM");
+
   // OpenCL definitions.
   if (LangOpts.OpenCL) {
 #define OPENCLEXT(Ext) \

lib/Headers/cpuid.h

 #define bit_SMEP        0x00000080
 #define bit_ENH_MOVSB   0x00000200
 
+#ifndef __CLANG_NO_GNU_INLINE_ASM
+
 #if __i386__
 #define __cpuid(__level, __eax, __ebx, __ecx, __edx) \
     __asm("cpuid" : "=a"(__eax), "=b" (__ebx), "=c"(__ecx), "=d"(__edx) \

         *__sig = __ebx;
     return __eax;
 }
+
+#endif /* __CLANG_NO_GNU_INLINE_ASM */

test/Driver/inline-asm.c

 // RUN: FileCheck --check-prefix=CHECK-NO-GNU-INLINE-ASM %s
 
 // CHECK-NO-GNU-INLINE-ASM: "-fno-gnu-inline-asm"
+
+// RUN: %clang -target x86_64-apple-darwin10 \
+// RUN:   -fno-gnu-inline-asm -dM -E %s 2>&1 | \
+// RUN: FileCheck --check-prefix=CHECK-NO-GNU-INLINE-ASM-DEFINE %s
+
+// CHECK-NO-GNU-INLINE-ASM-DEFINE: #define __CLANG_NO_GNU_INLINE_ASM 1