Add ms_abi and sysv_abi attribute handling.

Based on a patch by Benno Rice!

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@189644 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGCall.cpp b/lib/CodeGen/CGCall.cpp
index ed02c74..8a67279 100644
--- a/lib/CodeGen/CGCall.cpp
+++ b/lib/CodeGen/CGCall.cpp
@@ -41,6 +41,8 @@
   case CC_X86StdCall: return llvm::CallingConv::X86_StdCall;
   case CC_X86FastCall: return llvm::CallingConv::X86_FastCall;
   case CC_X86ThisCall: return llvm::CallingConv::X86_ThisCall;
+  case CC_X86_64Win64: return llvm::CallingConv::X86_64_Win64;
+  case CC_X86_64SysV: return llvm::CallingConv::X86_64_SysV;
   case CC_AAPCS: return llvm::CallingConv::ARM_AAPCS;
   case CC_AAPCS_VFP: return llvm::CallingConv::ARM_AAPCS_VFP;
   case CC_IntelOclBicc: return llvm::CallingConv::Intel_OCL_BI;