[es6] Implement spec compliant ToPrimitive in the runtime.

src/macros.py

Index: src/macros.py
diff --git a/src/macros.py b/src/macros.py
index b0228da9a59de5c1f22a384cb02205f9a69e6a27..03c2012593346e4cb0021e84ae74489fe71a16e0 100644
--- a/src/macros.py
+++ b/src/macros.py
@@ -153,6 +153,9 @@ macro TO_UINT32(arg) = (arg >>> 0);
 macro TO_STRING_INLINE(arg) = (IS_STRING(%IS_VAR(arg)) ? arg : $nonStringToString(arg));
 macro TO_NUMBER_INLINE(arg) = (IS_NUMBER(%IS_VAR(arg)) ? arg : $nonNumberToNumber(arg));
 macro TO_OBJECT(arg) = (%_ToObject(arg));
+macro TO_PRIMITIVE(arg) = (%_ToPrimitive(arg));
+macro TO_PRIMITIVE_NUMBER(arg) = (%_ToPrimitive_Number(arg));
+macro TO_PRIMITIVE_STRING(arg) = (%_ToPrimitive_String(arg));
 macro JSON_NUMBER_TO_STRING(arg) = ((%_IsSmi(%IS_VAR(arg)) || arg - arg == 0) ? %_NumberToString(arg) : "null");
 macro HAS_OWN_PROPERTY(arg, index) = (%_CallFunction(arg, index, ObjectHasOwnProperty));
 macro SHOULD_CREATE_WRAPPER(functionName, receiver) = (!IS_SPEC_OBJECT(receiver) && %IsSloppyModeFunction(functionName));