[runtime] Replace %to_string_fun with %_ToString.

src/runtime.js

Index: src/runtime.js
diff --git a/src/runtime.js b/src/runtime.js
index 89a3f2241dd9e95beefe7733fc282b42a1b5fd83..18efec36f5ee4703d03555d94d92ac1442539446 100644
--- a/src/runtime.js
+++ b/src/runtime.js
@@ -165,7 +165,7 @@ function ADD(x) {
   var b = %to_primitive(x, NO_HINT);
 
   if (IS_STRING(a)) {
-    return %_StringAdd(a, %to_string_fun(b));
+    return %_StringAdd(a, TO_STRING(b));
   } else if (IS_STRING(b)) {
     return %_StringAdd(%non_string_to_string(a), b);
   } else {
@@ -191,7 +191,7 @@ function STRING_ADD_LEFT(y) {
     } else {
       y = IS_NUMBER(y)
           ? %_NumberToString(y)
-          : %to_string_fun(%to_primitive(y, NO_HINT));
+          : TO_STRING(%to_primitive(y, NO_HINT));
     }
   }
   return %_StringAdd(this, y);
@@ -207,7 +207,7 @@ function STRING_ADD_RIGHT(y) {
     } else {
       x = IS_NUMBER(x)
           ? %_NumberToString(x)
-          : %to_string_fun(%to_primitive(x, NO_HINT));
+          : TO_STRING(%to_primitive(x, NO_HINT));
     }
   }
   return %_StringAdd(x, y);
@@ -495,7 +495,7 @@ function APPLY_PREPARE(args) {
   if (length > kSafeArgumentsLength) throw %make_range_error(kStackOverflow);
 
   if (!IS_SPEC_FUNCTION(this)) {
-    throw %make_type_error(kApplyNonFunction, %to_string_fun(this), typeof this);
+    throw %make_type_error(kApplyNonFunction, TO_STRING(this), typeof this);
   }
 
   // Make sure the arguments list has the right type.
@@ -523,7 +523,7 @@ function REFLECT_APPLY_PREPARE(args) {
   }
 
   if (!IS_SPEC_FUNCTION(this)) {
-    throw %make_type_error(kCalledNonCallable, %to_string_fun(this));
+    throw %make_type_error(kCalledNonCallable, TO_STRING(this));
   }
 
   if (!IS_SPEC_OBJECT(args)) {
@@ -562,17 +562,17 @@ function REFLECT_CONSTRUCT_PREPARE(
 
   if (!ctorOk) {
     if (!IS_SPEC_FUNCTION(this)) {
-      throw %make_type_error(kCalledNonCallable, %to_string_fun(this));
+      throw %make_type_error(kCalledNonCallable, TO_STRING(this));
     } else {
-      throw %make_type_error(kNotConstructor, %to_string_fun(this));
+      throw %make_type_error(kNotConstructor, TO_STRING(this));
     }
   }
 
   if (!newTargetOk) {
     if (!IS_SPEC_FUNCTION(newTarget)) {
-      throw %make_type_error(kCalledNonCallable, %to_string_fun(newTarget));
+      throw %make_type_error(kCalledNonCallable, TO_STRING(newTarget));
     } else {
-      throw %make_type_error(kNotConstructor, %to_string_fun(newTarget));
+      throw %make_type_error(kNotConstructor, TO_STRING(newTarget));
     }
   }
 
@@ -609,12 +609,6 @@ function TO_NUMBER() {
 }
 
 
-// Convert the receiver to a string - forward to ToString.
-function TO_STRING() {
-  return %to_string_fun(this);
-}
-
-
 /* -------------------------------------
    - - -   C o n v e r s i o n s   - - -
    -------------------------------------
@@ -873,7 +867,6 @@ $toString = ToString;
   "to_length_fun", ToLength,
   "to_number_fun", ToNumber,
   "to_primitive", ToPrimitive,
-  "to_string_fun", ToString,
 ]);
 
 utils.Export(function(to) {