[AArch64] Ignore stdcall and similar on aarch64/windows

This is similar to what's done on arm and x86_64, where
these calling conventions are silently ignored, as in
SVN r245076.

Differential Revision: https://reviews.llvm.org/D36105

llvm-svn: 310303
diff --git a/clang/lib/Basic/Targets/AArch64.cpp b/clang/lib/Basic/Targets/AArch64.cpp
index 16c4c21..af2e35b 100644
--- a/clang/lib/Basic/Targets/AArch64.cpp
+++ b/clang/lib/Basic/Targets/AArch64.cpp
@@ -458,6 +458,23 @@
   return TargetInfo::CharPtrBuiltinVaList;
 }
 
+TargetInfo::CallingConvCheckResult
+MicrosoftARM64TargetInfo::checkCallingConvention(CallingConv CC) const {
+  switch (CC) {
+  case CC_X86StdCall:
+  case CC_X86ThisCall:
+  case CC_X86FastCall:
+  case CC_X86VectorCall:
+    return CCCR_Ignore;
+  case CC_C:
+  case CC_OpenCLKernel:
+  case CC_Win64:
+    return CCCR_OK;
+  default:
+    return CCCR_Warning;
+  }
+}
+
 DarwinAArch64TargetInfo::DarwinAArch64TargetInfo(const llvm::Triple &Triple,
                                                  const TargetOptions &Opts)
     : DarwinTargetInfo<AArch64leTargetInfo>(Triple, Opts) {
diff --git a/clang/lib/Basic/Targets/AArch64.h b/clang/lib/Basic/Targets/AArch64.h
index 2375868..a720791 100644
--- a/clang/lib/Basic/Targets/AArch64.h
+++ b/clang/lib/Basic/Targets/AArch64.h
@@ -105,6 +105,8 @@
                         MacroBuilder &Builder) const override;
 
   BuiltinVaListKind getBuiltinVaListKind() const override;
+
+  CallingConvCheckResult checkCallingConvention(CallingConv CC) const override;
 };
 
 class LLVM_LIBRARY_VISIBILITY AArch64beTargetInfo : public AArch64TargetInfo {