Remove stale comments (334261 followup, r=self).

js/src/jsnum.h

@@ -46,9 +46,6 @@
  * but floating point literals, results that overflow 31 bits, and division and
  * modulus operands and results require a 64-bit IEEE double.  These are GC'ed
  * and pointed to by 32-bit jsvals on the stack and in object properties.
- *
- * When a JS number is treated as an object (followed by . or []), the runtime
- * wraps it with a JSObject whose valueOf method returns the unwrapped number.
  */
 
 JS_BEGIN_EXTERN_C

js/src/jsstr.h

@@ -47,10 +47,6 @@
  * necessitating a pointer after the count, to form a separately allocated
  * string descriptor.  String descriptors are GC'ed, while their chars are
  * allocated from the malloc heap.
- *
- * When a string is treated as an object (by following it with . or []), the
- * runtime wraps it with a JSObject whose valueOf method returns the unwrapped
- * string descriptor.
  */
 #include <ctype.h>
 #include "jspubtd.h"