Add a DIELocList class to handle pointers into the location list.
This enables us to figure out where in the debug_loc section our
locations are so that we can eventually hash them. It also helps
remove some special case code in emission. No functional change.

llvm-svn: 203018
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
index 315544b..c74d76a 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -751,6 +751,9 @@
   /// Returns the Dwarf Version.
   unsigned getDwarfVersion() const { return DwarfVersion; }
 
+  /// Returns the section symbol for the .debug_loc section.
+  MCSymbol *getDebugLocSym() const { return DwarfDebugLocSectionSym; }
+
   /// Find the MDNode for the given reference.
   template <typename T> T resolve(DIRef<T> Ref) const {
     return Ref.resolve(TypeIdentifierMap);