add support, testcases, and dox for the new GHC calling
convention.  Patch by David Terei!



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98212 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86FastISel.cpp b/lib/Target/X86/X86FastISel.cpp
index 98e3f4e..27807f2 100644
--- a/lib/Target/X86/X86FastISel.cpp
+++ b/lib/Target/X86/X86FastISel.cpp
@@ -172,7 +172,9 @@
 CCAssignFn *X86FastISel::CCAssignFnForCall(CallingConv::ID CC,
                                            bool isTaillCall) {
   if (Subtarget->is64Bit()) {
-    if (Subtarget->isTargetWin64())
+    if (CC == CallingConv::GHC)
+      return CC_X86_64_GHC;
+    else if (Subtarget->isTargetWin64())
       return CC_X86_Win64_C;
     else
       return CC_X86_64_C;
@@ -182,6 +184,8 @@
     return CC_X86_32_FastCall;
   else if (CC == CallingConv::Fast)
     return CC_X86_32_FastCC;
+  else if (CC == CallingConv::GHC)
+    return CC_X86_32_GHC;
   else
     return CC_X86_32_C;
 }