Add convenient helper for win64 check. Simplify things slightly.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48691 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86Subtarget.h b/lib/Target/X86/X86Subtarget.h
index e34d1f1..6488d47 100644
--- a/lib/Target/X86/X86Subtarget.h
+++ b/lib/Target/X86/X86Subtarget.h
@@ -138,6 +138,9 @@
   bool isTargetCygMing() const { return (TargetType == isMingw ||
                                          TargetType == isCygwin); }
   bool isTargetCygwin() const { return TargetType == isCygwin; }
+  bool isTargetWin64() const {
+    return (Is64Bit && (TargetType == isMingw || TargetType == isWindows));
+  }
 
   std::string getDataLayout() const {
     const char *p;