- Export JSSLOT_ITER_* from jsiter.cpp to jsiter.h, for jstracer.cpp to use.

- Fix OBJ_GET_SLOT to be STOBJ_GET_SLOT in jsiter.cpp, no thread safety here (bug on file).
- Move JSNativeEnumerator from jsobj.cpp to jsobj.h for jstracer.cpp as well.
- Rename JOF_2BYTE JOF_UINT8 for consistency, and actually decompile it.
- Trace JSOP_FORVAR (can't do anything in JSOP_ITER, it comes before the loop).
- Shortened some guardMyLongSummerVacationWithinBounds names ;-).
- Removed/refactored to avoid dslots_ins obligation on all callers.

js/src/jsopcode.h

@@ -76,7 +76,7 @@ typedef enum JSOp {
 #define JOF_TABLESWITCHX  10      /* extended (32-bit offset) table switch */
 #define JOF_LOOKUPSWITCHX 11      /* extended (32-bit offset) lookup switch */
 #define JOF_UINT24        12      /* extended unsigned 24-bit literal (index) */
-#define JOF_2BYTE         13      /* 2-byte opcode, e.g., upper 8 bits of 24-bit
+#define JOF_UINT8         13      /* uint8 immediate, e.g. top 8 bits of 24-bit
                                      atom index */
 #define JOF_LOCAL         14      /* block-local operand stack variable */
 #define JOF_OBJECT        15      /* unsigned 16-bit object pool index */