PR14964: intrinsic headers using non-reserved identifiers

Several of the intrinsic headers were using plain non-reserved identifiers.
C++11 17.6.4.3.2 [global.names] p1 reservers names containing a double
begining with an underscore followed by an uppercase letter for any use.

I think I got them all, but open to being corrected. For the most part I
didn't bother updating function-like macro parameter names because I don't
believe they're subject to any such collission - though some function-like
macros already follow this convention (I didn't update them in part because
the churn was more significant as several function-like macros use the double
underscore prefixed version of the same name as a parameter in their
implementation)

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@172666 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Headers/cpuid.h b/lib/Headers/cpuid.h
index 33df7c2..6d7d61d 100644
--- a/lib/Headers/cpuid.h
+++ b/lib/Headers/cpuid.h
@@ -25,9 +25,10 @@
 #error this header is for x86 only
 #endif
 
-static inline int __get_cpuid (unsigned int level, unsigned int *eax,
-                               unsigned int *ebx, unsigned int *ecx,
-                               unsigned int *edx) {
-    __asm("cpuid" : "=a"(*eax), "=b" (*ebx), "=c"(*ecx), "=d"(*edx) : "0"(level));
+static inline int __get_cpuid (unsigned int __level, unsigned int *__eax,
+                               unsigned int *__ebx, unsigned int *__ecx,
+                               unsigned int *__edx) {
+    __asm("cpuid" : "=a"(*__eax), "=b" (*__ebx), "=c"(*__ecx), "=d"(*__edx)
+                  : "0"(__level));
     return 1;
 }