IR: Represent -ggnu-pubnames with a flag on the DICompileUnit.

This allows the flag to be persisted through to LTO.

Differential Revision: https://reviews.llvm.org/D37655

llvm-svn: 313078

llvm/lib/Bitcode/Writer/BitcodeWriter.cpp

@@ -1555,6 +1555,7 @@ void ModuleBitcodeWriter::writeDICompileUnit(const DICompileUnit *N,
   Record.push_back(VE.getMetadataOrNullID(N->getMacros().get()));
   Record.push_back(N->getSplitDebugInlining());
   Record.push_back(N->getDebugInfoForProfiling());
+  Record.push_back(N->getGnuPubnames());
 
   Stream.EmitRecord(bitc::METADATA_COMPILE_UNIT, Record, Abbrev);
   Record.clear();