Start porting fast typechecks to x64.

runtime/vm/intermediate_language.h

Index: runtime/vm/intermediate_language.h
===================================================================
--- runtime/vm/intermediate_language.h	(revision 7716)
+++ runtime/vm/intermediate_language.h	(working copy)
@@ -232,12 +232,14 @@
   AssertAssignableComp(intptr_t token_index,
                        intptr_t try_index,
                        Value* value,
+                       Value* instantiator,  // Can be NULL.
                        Value* instantiator_type_arguments,  // Can be NULL.
                        const AbstractType& dst_type,
                        const String& dst_name)
       : token_index_(token_index),
         try_index_(try_index),
         value_(value),
+        instantiator_(instantiator),
         instantiator_type_arguments_(instantiator_type_arguments),
         dst_type_(dst_type),
         dst_name_(dst_name) {
@@ -251,6 +253,7 @@
   intptr_t token_index() const { return token_index_; }
   intptr_t try_index() const { return try_index_; }
   Value* value() const { return value_; }
+  Value* instantiator() const { return instantiator_; }
   Value* instantiator_type_arguments() const {
     return instantiator_type_arguments_;
   }
@@ -263,6 +266,7 @@
   const intptr_t token_index_;
   const intptr_t try_index_;
   Value* value_;
+  Value* instantiator_;
   Value* instantiator_type_arguments_;
   const AbstractType& dst_type_;
   const String& dst_name_;
@@ -769,12 +773,14 @@
   InstanceOfComp(intptr_t token_index,
                  intptr_t try_index,
                  Value* value,
+                 Value* instantiator,  // Can be NULL.
                  Value* type_arguments,  // Can be NULL.
                  const AbstractType& type,
                  bool negate_result)
       : token_index_(token_index),
         try_index_(try_index),
         value_(value),
+        instantiator_(instantiator),
         type_arguments_(type_arguments),
         type_(type),
         negate_result_(negate_result) {
@@ -785,6 +791,7 @@
   DECLARE_COMPUTATION(InstanceOf)
 
   Value* value() const { return value_; }
+  Value* instantiator() const { return instantiator_; }
   Value* type_arguments() const { return type_arguments_; }
   bool negate_result() const { return negate_result_; }
   const AbstractType& type() const { return type_; }
@@ -797,6 +804,7 @@
   const intptr_t token_index_;
   const intptr_t try_index_;
   Value* value_;
+  Value* instantiator_;
   Value* type_arguments_;
   const AbstractType& type_;
   const bool negate_result_;