Use a reference rather than a pointer as we don't expect a NULL
DbgVariable.

No functional change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194761 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h
index ffb87dd..1fd40fb 100644
--- a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h
+++ b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h
@@ -317,7 +317,7 @@
   void constructContainingTypeDIEs();
 
   /// constructVariableDIE - Construct a DIE for the given DbgVariable.
-  DIE *constructVariableDIE(DbgVariable *DV, bool isScopeAbstract);
+  DIE *constructVariableDIE(DbgVariable &DV, bool isScopeAbstract);
 
   /// Create a DIE with the given Tag, add the DIE to its parent, and
   /// call insertDIE if MD is not null.