Make X86 call and return instructions non-variadic.

Function argument and return value registers aren't part of the
encoding, so they should be implicit operands.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159728 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86FrameLowering.cpp b/lib/Target/X86/X86FrameLowering.cpp
index a65bc15..7e7f364 100644
--- a/lib/Target/X86/X86FrameLowering.cpp
+++ b/lib/Target/X86/X86FrameLowering.cpp
@@ -1124,8 +1124,7 @@
     }
 
     MachineInstr *NewMI = prior(MBBI);
-    for (unsigned i = 2, e = MBBI->getNumOperands(); i != e; ++i)
-      NewMI->addOperand(MBBI->getOperand(i));
+    NewMI->copyImplicitOps(MBBI);
 
     // Delete the pseudo instruction TCRETURN.
     MBB.erase(MBBI);