VM: Enable branch merging of isnan, isinf.

runtime/vm/intermediate_language.cc

Index: runtime/vm/intermediate_language.cc
diff --git a/runtime/vm/intermediate_language.cc b/runtime/vm/intermediate_language.cc
index f3af736017344d973af143f0602ecbd3f1c8e609..fec4664478a654de9461b15388aba2c33012e3b7 100644
--- a/runtime/vm/intermediate_language.cc
+++ b/runtime/vm/intermediate_language.cc
@@ -3020,13 +3020,13 @@ StrictCompareInstr::StrictCompareInstr(TokenPosition token_pos,
                                        Value* left,
                                        Value* right,
                                        bool needs_number_check)
-    : ComparisonInstr(token_pos,
-                      kind,
-                      left,
-                      right,
-                      Thread::Current()->GetNextDeoptId()),
+    : TemplateComparison(token_pos,
+                         kind,
+                         Thread::Current()->GetNextDeoptId()),
       needs_number_check_(needs_number_check) {
   ASSERT((kind == Token::kEQ_STRICT) || (kind == Token::kNE_STRICT));
+  SetInputAt(0, left);
+  SetInputAt(1, right);
 }
 
 
@@ -3422,6 +3422,13 @@ void Environment::DeepCopyToOuter(Zone* zone, Instruction* instr) const {
 }
 
 
+ComparisonInstr* DoubleTestOpInstr::CopyWithNewOperands(Value* new_left,
+                                                        Value* new_right) {
+  UNREACHABLE();
+  return NULL;
+}
+
+
 ComparisonInstr* EqualityCompareInstr::CopyWithNewOperands(Value* new_left,
                                                            Value* new_right) {
   return new EqualityCompareInstr(token_pos(),