Add a new routine Sema::LookupDestructor and make all destructor-lookup calls use that routine

llvm-svn: 107444
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 27455db..c1d670c 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -5951,7 +5951,7 @@
 
   case CXXDestructor:
     if (RD->hasUserDeclaredDestructor()) {
-      SourceLocation DtorLoc = RD->getDestructor()->getLocation();
+      SourceLocation DtorLoc = LookupDestructor(RD)->getLocation();
       Diag(DtorLoc, diag::note_nontrivial_user_defined) << QT << member;
       return;
     }