Minor cleanups to a few llvm_unreachable() calls.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119767 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMCodeEmitter.cpp b/lib/Target/ARM/ARMCodeEmitter.cpp
index 8888420..ef0ef80 100644
--- a/lib/Target/ARM/ARMCodeEmitter.cpp
+++ b/lib/Target/ARM/ARMCodeEmitter.cpp
@@ -378,12 +378,8 @@
     emitJumpTableAddress(MO.getIndex(), ARM::reloc_arm_relative);
   else if (MO.isMBB())
     emitMachineBasicBlock(MO.getMBB(), ARM::reloc_arm_branch);
-  else {
-#ifndef NDEBUG
-    errs() << MO;
-#endif
-    llvm_unreachable(0);
-  }
+  else
+    llvm_unreachable("Unable to encode MachineOperand!");
   return 0;
 }