[Support] Silence function cast warning when building with Clang ToT targetting Windows

Author: aganea

llvm/lib/Support/Windows/Process.inc

@@ -482,9 +482,18 @@ static RTL_OSVERSIONINFOEXW GetWindowsVer() {
     HMODULE hMod = ::GetModuleHandleW(L"ntdll.dll");
     assert(hMod);
 
+#if defined(__clang__)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wcast-function-type-mismatch"
+#endif
+
     auto getVer = (RtlGetVersionPtr)::GetProcAddress(hMod, "RtlGetVersion");
     assert(getVer);
 
+#if defined(__clang__)
+#pragma clang diagnostic pop
+#endif
+
     RTL_OSVERSIONINFOEXW info{};
     info.dwOSVersionInfoSize = sizeof(info);
     NTSTATUS r = getVer((PRTL_OSVERSIONINFOW)&info);

llvm/lib/Support/Windows/Signals.inc

@@ -167,6 +167,11 @@ static bool isDebugHelpInitialized() {
   return fStackWalk64 && fSymInitialize && fSymSetOptions && fMiniDumpWriteDump;
 }
 
+#if defined(__clang__)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wcast-function-type-mismatch"
+#endif
+
 static bool load64BitDebugHelp(void) {
   HMODULE hLib =
       ::LoadLibraryExA("Dbghelp.dll", NULL, LOAD_LIBRARY_SEARCH_SYSTEM32);
@@ -192,6 +197,10 @@ static bool load64BitDebugHelp(void) {
   return isDebugHelpInitialized();
 }
 
+#if defined(__clang__)
+#pragma clang diagnostic pop
+#endif
+
 using namespace llvm;
 
 // Forward declare.