Implement IS_OBJECT and IS_FUNCTION as inlined runtime functions....

src/macros.py

Index: src/macros.py
===================================================================
--- src/macros.py	(revision 3334)
+++ src/macros.py	(working copy)
@@ -79,11 +79,10 @@
 macro IS_UNDEFINED(arg)         = (typeof(arg) === 'undefined');
 macro IS_NUMBER(arg)            = (typeof(arg) === 'number');
 macro IS_STRING(arg)            = (typeof(arg) === 'string');
-macro IS_OBJECT(arg)            = (typeof(arg) === 'object' || %_ClassOf(arg) == 'RegExp');
 macro IS_BOOLEAN(arg)           = (typeof(arg) === 'boolean');
+macro IS_OBJECT(arg)            = (%_IsObject(arg));
 macro IS_ARRAY(arg)             = (%_IsArray(arg));
-# IS_FUNCTION uses %_ClassOf rather than typeof so as to exclude regexps.
-macro IS_FUNCTION(arg)          = (%_ClassOf(arg) === 'Function');
+macro IS_FUNCTION(arg)          = (%_IsFunction(arg));
 macro IS_REGEXP(arg)            = (%_ClassOf(arg) === 'RegExp');
 macro IS_DATE(arg)              = (%_ClassOf(arg) === 'Date');
 macro IS_NUMBER_WRAPPER(arg)    = (%_ClassOf(arg) === 'Number');