[vm/compiler] Refine type information when replacing definitions.

This way, the new type information can be used immediately by
this and following passes instead of only passes after the next
type propagation phase.

Change-Id: Id27c3789c7c32f5775da5ef933bc56cb58c2a203
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/101826
Commit-Queue: Teagan Strickland <sstrickl@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>

runtime/vm/compiler/backend/il.cc

@@ -1312,6 +1312,7 @@ void Definition::ReplaceUsesWith(Definition* other) {
     while (next != NULL) {
       current = next;
       current->set_definition(other);
+      current->RefineReachingType(other->Type());
       next = current->next_use();
     }
 
@@ -1330,6 +1331,7 @@ void Definition::ReplaceUsesWith(Definition* other) {
     while (next != NULL) {
       current = next;
       current->set_definition(other);
+      current->RefineReachingType(other->Type());
       next = current->next_use();
     }
     next = other->env_use_list();

runtime/vm/compiler/backend/redundancy_elimination_test.cc

@@ -679,7 +679,33 @@ ISOLATE_UNIT_TEST_CASE(LoadOptimizer_AliasingViaLoadElimination_AcrossBlocks) {
   Invoke(root_library, "main");
 
   TestPipeline pipeline(function, CompilerPass::kJIT);
-  FlowGraph* flow_graph = pipeline.RunPasses({});
+  // Recent changes actually compile the function into a single basic
+  // block, so we need to test right after the load optimizer has been run.
+  // Have checked that this test still fails appropriately using the load
+  // optimizer prior to the fix (commit 2a237327).
+  FlowGraph* flow_graph = pipeline.RunPasses({
+      CompilerPass::kComputeSSA,
+      CompilerPass::kApplyICData,
+      CompilerPass::kTryOptimizePatterns,
+      CompilerPass::kSetOuterInliningId,
+      CompilerPass::kTypePropagation,
+      CompilerPass::kApplyClassIds,
+      CompilerPass::kInlining,
+      CompilerPass::kTypePropagation,
+      CompilerPass::kApplyClassIds,
+      CompilerPass::kTypePropagation,
+      CompilerPass::kApplyICData,
+      CompilerPass::kCanonicalize,
+      CompilerPass::kBranchSimplify,
+      CompilerPass::kIfConvert,
+      CompilerPass::kCanonicalize,
+      CompilerPass::kConstantPropagation,
+      CompilerPass::kOptimisticallySpecializeSmiPhis,
+      CompilerPass::kTypePropagation,
+      CompilerPass::kWidenSmiToInt32,
+      CompilerPass::kSelectRepresentations,
+      CompilerPass::kCSE,
+  });
 
   auto entry = flow_graph->graph_entry()->normal_entry();
   EXPECT(entry != nullptr);
@@ -698,6 +724,7 @@ ISOLATE_UNIT_TEST_CASE(LoadOptimizer_AliasingViaLoadElimination_AcrossBlocks) {
           kMatchAndMoveBranchTrue,
           kMatchAndMoveBranchTrue,
           kMatchAndMoveBranchFalse,
+          kMatchAndMoveBranchFalse,
           {kMatchAndMoveUnboxedConstant, &double_one},
           {kMatchAndMoveStoreIndexed, &first_store},
           kMatchAndMoveBranchFalse,