Initial support for polymorphic inlining.

runtime/vm/flow_graph.cc

Index: runtime/vm/flow_graph.cc
diff --git a/runtime/vm/flow_graph.cc b/runtime/vm/flow_graph.cc
index 34ca6932d6aad8b34e57e39fe44fab42b493ba5d..8f9e48c4efecf70000a6e56e85356ea0a59e742e 100644
--- a/runtime/vm/flow_graph.cc
+++ b/runtime/vm/flow_graph.cc
@@ -522,7 +522,6 @@ void FlowGraph::ComputeDominators(
       dom_index = idom[dom_index];
     }
     idom[block_index] = dom_index;
-    preorder_[block_index]->set_dominator(preorder_[dom_index]);
     preorder_[dom_index]->AddDominatedBlock(preorder_[block_index]);
   }
 
@@ -847,6 +846,28 @@ void FlowGraph::RemoveDeadPhis(GrowableArray<PhiInstr*>* live_phis) {
 }
 
 
+void FlowGraph::RemoveRedefinitions() {
+  // Remove redefinition instructions inserted to inhibit hoisting.
+  for (BlockIterator block_it = reverse_postorder_iterator();
+       !block_it.Done();
+       block_it.Advance()) {
+    for (ForwardInstructionIterator instr_it(block_it.Current());
+         !instr_it.Done();
+         instr_it.Advance()) {
+      RedefinitionInstr* redefinition = instr_it.Current()->AsRedefinition();
+      if (redefinition != NULL) {
+        Definition* original;
+        do {
+          original = redefinition->value()->definition();
+        } while (original->IsRedefinition());
+        redefinition->ReplaceUsesWith(original);
+        instr_it.RemoveCurrentFromGraph();
+      }
+    }
+  }
+}
+
+
 // Find the natural loop for the back edge m->n and attach loop information
 // to block n (loop header). The algorithm is described in "Advanced Compiler
 // Design & Implementation" (Muchnick) p192.