SF patch #701907: More use of fast_next_opcode
SF patch #701907: More use of fast_next_opcode

My previous patches should have used fast_next_opcode
in a few places instead of continue.

Also, applied one PyInt_AS_LONG macro in a place where
the type had already been checked.

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator