DIEEntry: Refer to the specified DIE via reference rather than pointer.

Makes some more cases (the unit tests, specifically), lexically
compatible with a change to unique_ptr.

llvm-svn: 207261
diff --git a/llvm/lib/CodeGen/AsmPrinter/DIEHash.cpp b/llvm/lib/CodeGen/AsmPrinter/DIEHash.cpp
index 3946dc3..c2fad59 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DIEHash.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DIEHash.cpp
@@ -309,7 +309,7 @@
     // ... An attribute that refers to another type entry T is processed as
     // follows:
   case DIEValue::isEntry:
-    hashDIEEntry(Attribute, Tag, *cast<DIEEntry>(Value)->getEntry());
+    hashDIEEntry(Attribute, Tag, cast<DIEEntry>(Value)->getEntry());
     break;
   case DIEValue::isInteger: {
     addULEB128('A');