Changed the semantics of program_index_no_free() somewhat in preparation for having symbols with storage in parent classes.
Changed the representation of tentatively typed function identifiers.
They are now marked by having the run time type T_MIXED.
Changed the encoding in the identifier_flags field somewhat to free up a bit to indicate that the symbol has storage in an external scope.
Bumped version to 7.7.36 since the dump format for programs has changed.
Fixed minor bug in index_no_free() when indexing a function that wasn't a program.