CodeGen: Change MachineInstr to use MachineInstr&, NFC

Change MachineInstr API to prefer MachineInstr& over MachineInstr*
whenever the parameter is expected to be non-null.  Slowly inching
toward being able to fix PR26753.

llvm-svn: 262149
diff --git a/llvm/lib/Target/X86/X86ExpandPseudo.cpp b/llvm/lib/Target/X86/X86ExpandPseudo.cpp
index a09d065..de89dfd 100644
--- a/llvm/lib/Target/X86/X86ExpandPseudo.cpp
+++ b/llvm/lib/Target/X86/X86ExpandPseudo.cpp
@@ -122,7 +122,7 @@
     }
 
     MachineInstr *NewMI = std::prev(MBBI);
-    NewMI->copyImplicitOps(*MBBI->getParent()->getParent(), MBBI);
+    NewMI->copyImplicitOps(*MBBI->getParent()->getParent(), *MBBI);
 
     // Delete the pseudo instruction TCRETURN.
     MBB.erase(MBBI);