Fix bogus assertion failures


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@4919 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86CodeEmitter.cpp b/lib/Target/X86/X86CodeEmitter.cpp
index d54da1d..4039f34 100644
--- a/lib/Target/X86/X86CodeEmitter.cpp
+++ b/lib/Target/X86/X86CodeEmitter.cpp
@@ -225,7 +225,7 @@
     MCE.emitByte(BaseOpcode + getX86RegNum(MI.getOperand(0).getReg()));
     if (MI.getNumOperands() == 2) {
       unsigned Size = 4;
-      if (Value *V = MI.getOperand(1).getVRegValue()) {
+      if (Value *V = MI.getOperand(1).getVRegValueOrNull()) {
         assert(Size == 4 && "Don't know how to emit non-pointer values!");
         MCE.emitGlobalAddress(cast<GlobalValue>(V));
       } else {