[DAGCombiner] Add combined indexed load to the work list

This commit is the first part of https://reviews.llvm.org/D40348.
In order to allow target combines to be performed on newly combined
indexed loads, add them back to the worklist. The remainder of the
above patch will be committed in subsequent revisions and will use
this. Test cases will be included with those follow-up commits.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@320365 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/SelectionDAG/DAGCombiner.cpp

@@ -11380,6 +11380,7 @@ bool DAGCombiner::CombineToPreIndexedLoadStore(SDNode *N) {
   // Replace the uses of Ptr with uses of the updated base value.
   DAG.ReplaceAllUsesOfValueWith(Ptr, Result.getValue(isLoad ? 1 : 0));
   deleteAndRecombine(Ptr.getNode());
+  AddToWorklist(Result.getNode());
 
   return true;
 }