lib/CodeGen/TargetInfo.cpp: Add Win64 calling conversion.

FIXME: It would be incompatible to Microsoft's in one point.
On mingw64-gcc, {i128} is expanded for args and returned as {rax, rdx}.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@123692 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed