Plug a leak when using MCJIT.

Found by valgrind.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157160 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LLVMTargetMachine.cpp b/lib/CodeGen/LLVMTargetMachine.cpp
index 313d362..30963a2 100644
--- a/lib/CodeGen/LLVMTargetMachine.cpp
+++ b/lib/CodeGen/LLVMTargetMachine.cpp
@@ -273,7 +273,7 @@
 
   // Create the code emitter for the target if it exists.  If not, .o file
   // emission fails.
-  const MCRegisterInfo &MRI = *getTarget().createMCRegInfo(getTargetTriple());
+  const MCRegisterInfo &MRI = *getRegisterInfo();
   const MCSubtargetInfo &STI = getSubtarget<MCSubtargetInfo>();
   MCCodeEmitter *MCE = getTarget().createMCCodeEmitter(*getInstrInfo(), MRI,
                                                        STI, *Ctx);