Peepholer could be fooled into misidentifying a tuple_of_constants.
Added code to count consecutive occurrences of LOAD_CONST.
Use the count to weed out the misidentified cases.
Added a unittest.
* Make a pass to eliminate NOPs. Produce code that is more readable,
more compact, and a tiny bit faster. Makes the peepholer more flexible
in the scope of allowable transformations.
* With Guido's okay, bumped up the magic number so that this patch gets
widely exercised before the alpha goes out.