Debug Info: define a DIRef template.

Specialize the constructors for DIRef<DIScope> and DIRef<DIType> to make sure
the Value is indeed a scope ref and a type ref.

Use DIScopeRef for DIScope::getContext and DIType::getContext and use DITypeRef
for getContainingType and getClassType.

DIScope::generateRef now returns a DIScopeRef instead of a "Value *" for
readability and type safety.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190418 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/AsmPrinter/DwarfDebug.cpp

@@ -2644,8 +2644,3 @@ void DwarfDebug::emitDebugStrDWO() {
   InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
                          OffSec, StrSym);
 }
-
-/// Find the MDNode for the given scope reference.
-DIScope DwarfDebug::resolve(DIScopeRef SRef) const {
-  return SRef.resolve(TypeIdentifierMap);
-}