[LegacyPassManager] Add NL to -print-before/-print-after banner

[tpr]

Summary

Change-Id: Idc93e09a9b24ba723bf9f7cad315885eeb62916c

[fedor.sergeev]

I believe this is not a right place for a fix.
Banner in some cases is just a prefix for a full banner line
(see PrintFunctionPass::run, handling for forcePrintModuleIR).

So the right way to fix is to add \n in a couple of places where it is still missing
(say, in PrintFunctionPass::run, else branch of forcePrintModuleIR condition).

lib/IR/LegacyPassManager.cpp

if (ImmutablePass *IP = P->getAsImmutablePass()) {
     DM->initializeAnalysisImpl(P);
     addImmutablePass(IP);
     DM->recordAvailableAnalysis(IP);
     return;
   }
 
   if (PI && !PI->isAnalysis() && shouldPrintBeforePass(PI->getPassArgument())) {
     Pass *PP = P->createPrinterPass(
-        dbgs(), ("*** IR Dump Before " + P->getPassName() + " ***").str());
+        dbgs(), ("*** IR Dump Before " + P->getPassName() + " ***\n").str());
     PP->assignPassManager(activeStack, getTopLevelPassManagerType());
   }
 
   // Add the requested pass to the best available pass manager.
   P->assignPassManager(activeStack, getTopLevelPassManagerType());
 
   if (PI && !PI->isAnalysis() && shouldPrintAfterPass(PI->getPassArgument())) {
     Pass *PP = P->createPrinterPass(
-        dbgs(), ("*** IR Dump After " + P->getPassName() + " ***").str());
+        dbgs(), ("*** IR Dump After " + P->getPassName() + " ***\n").str());
     PP->assignPassManager(activeStack, getTopLevelPassManagerType());
   }
 }
 
 /// Find the pass that implements Analysis AID. Search immutable
 /// passes and all pass managers. If desired pass is not found
 /// then return NULL.
 Pass *PMTopLevelManager::findAnalysisPass(AnalysisID AID) {