[PM] Wire up support for writing bitcode with new PM.

This moves the old pass creation functionality to its own header and
updates the callers of that routine. Then it adds a new PM supporting
bitcode writer to the header file, and wires that up in the opt tool.
A test is added that round-trips code into bitcode and back out using
the new pass manager.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199078 91177308-0d34-0410-b5e6-96231b3b80d8

tools/opt/NewPMDriver.cpp

@@ -16,6 +16,7 @@
 #include "NewPMDriver.h"
 #include "Passes.h"
 #include "llvm/ADT/StringRef.h"
+#include "llvm/Bitcode/BitcodeWriterPass.h"
 #include "llvm/IR/IRPrintingPasses.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/Module.h"
@@ -44,7 +45,8 @@ bool llvm::runPassPipeline(StringRef Arg0, LLVMContext &Context, Module &M,
     MPM.addPass(PrintModulePass(Out->os()));
     break;
   case OK_OutputBitcode:
-    llvm::report_fatal_error("Bitcode output is not yet implemented!");
+    MPM.addPass(BitcodeWriterPass(Out->os()));
+    break;
   }
 
   // Before executing passes, print the final values of the LLVM options.

tools/opt/opt.cpp

@@ -20,7 +20,7 @@
 #include "llvm/Analysis/LoopPass.h"
 #include "llvm/Analysis/RegionPass.h"
 #include "llvm/Analysis/Verifier.h"
-#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/Bitcode/BitcodeWriterPass.h"
 #include "llvm/CodeGen/CommandFlags.h"
 #include "llvm/DebugInfo.h"
 #include "llvm/IR/DataLayout.h"