Allocate the contents of DwarfDebug's StringMaps in a single big BumpPtrAllocator.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158265 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/AsmPrinter/DwarfDebug.cpp

@@ -126,6 +126,7 @@ DIType DbgVariable::getType() const {
 DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
   : Asm(A), MMI(Asm->MMI), FirstCU(0),
     AbbreviationsSet(InitAbbreviationsSetSize),
+    SourceIdMap(DIEValueAllocator), StringPool(DIEValueAllocator),
     PrevLabel(NULL) {
   NextStringPoolNumber = 0;