[compiler-rt] Silence warnings when building with Clang ToT

Fixes several warnings such as:
```
C:\git\llvm-project\compiler-rt\lib\profile\InstrProfilingFile.c(760,18): warning: cast from 'const char *' to 'void *' drops const qualifier [-Wcast-qual]
  760 |     free((void *)lprofCurFilename.FilenamePat);
      |                  ^
3 warnings generated.
```

Author: aganea

compiler-rt/lib/profile/InstrProfilingFile.c

@@ -702,10 +702,15 @@ static void resetFilenameToDefault(void) {
 #ifdef __GNUC__
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wcast-qual"
+#elif defined(__clang__)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wcast-qual"
 #endif
     free((void *)lprofCurFilename.FilenamePat);
 #ifdef __GNUC__
 #pragma GCC diagnostic pop
+#elif defined(__clang__)
+#pragma clang diagnostic pop
 #endif
   }
   memset(&lprofCurFilename, 0, sizeof(lprofCurFilename));
@@ -751,6 +756,9 @@ static int parseFilenamePattern(const char *FilenamePat,
 #ifdef __GNUC__
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wcast-qual"
+#elif defined(__clang__)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wcast-qual"
 #endif
   /* Clean up cached prefix and filename.  */
   if (lprofCurFilename.ProfilePathPrefix)
@@ -761,6 +769,8 @@ static int parseFilenamePattern(const char *FilenamePat,
   }
 #ifdef __GNUC__
 #pragma GCC diagnostic pop
+#elif defined(__clang__)
+#pragma clang diagnostic pop
 #endif
 
   memset(&lprofCurFilename, 0, sizeof(lprofCurFilename));

compiler-rt/lib/profile/InstrProfilingMerge.c

@@ -41,6 +41,9 @@ uint64_t lprofGetLoadModuleSignature(void) {
 #ifdef __GNUC__
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wcast-qual"
+#elif defined(__clang__)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wcast-qual"
 #endif
 
 /* Returns 1 if profile is not structurally compatible.  */
@@ -234,4 +237,6 @@ int __llvm_profile_merge_from_buffer(const char *ProfileData,
 
 #ifdef __GNUC__
 #pragma GCC diagnostic pop
+#elif defined(__clang__)
+#pragma clang diagnostic pop
 #endif

compiler-rt/lib/profile/InstrProfilingValue.c

@@ -62,10 +62,15 @@ __llvm_profile_set_num_value_sites(__llvm_profile_data *Data,
 #ifdef __GNUC__
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wcast-qual"
+#elif defined(__clang__)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wcast-qual"
 #endif
   *((uint16_t *)&Data->NumValueSites[ValueKind]) = NumValueSites;
 #ifdef __GNUC__
 #pragma GCC diagnostic pop
+#elif defined(__clang__)
+#pragma clang diagnostic pop
 #endif
 }