VM: Remove PushTempInstr, simplify SSA renaming.

runtime/vm/intermediate_language.h

Index: runtime/vm/intermediate_language.h
diff --git a/runtime/vm/intermediate_language.h b/runtime/vm/intermediate_language.h
index 1536cf4cde887b45c60fe15c6f489d48fa7873f6..594355fb32308505e78e7f0ecb451e5c327276b0 100644
--- a/runtime/vm/intermediate_language.h
+++ b/runtime/vm/intermediate_language.h
@@ -454,7 +454,6 @@ class EmbeddedArray<T, 0> {
   M(PolymorphicInstanceCall)                                                   \
   M(StaticCall)                                                                \
   M(LoadLocal)                                                                 \
-  M(PushTemp)                                                                  \
   M(DropTemps)                                                                 \
   M(StoreLocal)                                                                \
   M(StrictCompare)                                                             \
@@ -3368,34 +3367,6 @@ class LoadLocalInstr : public TemplateDefinition<0, NoThrow> {
 };
 
 
-class PushTempInstr : public TemplateDefinition<1, NoThrow> {
- public:
-  explicit PushTempInstr(Value* value) {
-    SetInputAt(0, value);
-  }
-
-  DECLARE_INSTRUCTION(PushTemp)
-
-  Value* value() const { return inputs_[0]; }
-
-  virtual CompileType ComputeType() const;
-
-  virtual bool CanDeoptimize() const { return false; }
-
-  virtual EffectSet Effects() const {
-    UNREACHABLE();  // Eliminated by SSA construction.
-    return EffectSet::None();
-  }
-
-  virtual TokenPosition token_pos() const {
-    return TokenPosition::kTempMove;
-  }
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(PushTempInstr);
-};
-
-
 class DropTempsInstr : public Definition {
  public:
   DropTempsInstr(intptr_t num_temps, Value* value)