Merge (x & y) == 0 pattern to emit a single test instruction.

runtime/vm/flow_graph_type_propagator.cc

Index: runtime/vm/flow_graph_type_propagator.cc
===================================================================
--- runtime/vm/flow_graph_type_propagator.cc	(revision 29964)
+++ runtime/vm/flow_graph_type_propagator.cc	(working copy)
@@ -803,14 +803,14 @@
 }
 
 
-CompileType EqualityCompareInstr::ComputeType() const {
-  // Used for numeric comparisons only.
+CompileType TestSmiInstr::ComputeType() const {
   return CompileType::Bool();
 }
 
 
-bool EqualityCompareInstr::RecomputeType() {
-  return UpdateType(ComputeType());
+CompileType EqualityCompareInstr::ComputeType() const {
+  // Used for numeric comparisons only.
+  return CompileType::Bool();
 }
 
 
@@ -820,11 +820,6 @@
 }
 
 
-bool RelationalOpInstr::RecomputeType() {
-  return UpdateType(ComputeType());
-}
-
-
 CompileType CurrentContextInstr::ComputeType() const {
   return CompileType::FromCid(kContextCid);
 }