Add branch relaxation pass (shamelessly stolen from PPC).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93554 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/MSP430/MSP430TargetMachine.cpp

@@ -44,3 +44,9 @@ bool MSP430TargetMachine::addInstSelector(PassManagerBase &PM,
   return false;
 }
 
+bool MSP430TargetMachine::addPreEmitPass(PassManagerBase &PM,
+                                         CodeGenOpt::Level OptLevel) {
+  // Must run branch selection immediately preceding the asm printer.
+  PM.add(createMSP430BranchSelectionPass());
+  return false;
+}