Add in comments for BUILD_TUPLE in Python/ceval.c; Add in comments for Objects/tupleobject.c
add comment for PyTuple_New, which is used when allocating brand new tuples
annotate binary_op1
add comments for STORE_NAME's PyObject_SetItem()
Merged with Jeff's commit
Merge branch 'Qiyuan_Asgn02' of https://github.com/qiuqiyuan/cpython into Jeff_Asgn02