Update Android port

Update Android port

* src/sfnt.c (sfnt_decompose_compound_glyph): Allow decomposing
up to 16 nested components.
(CALL, LOOPCALL): Correctly error if no fdef storage exists.
(sfnt_interpret_run): New label `next_instruction', for CALL.
(sfnt_interpret_compound_glyph_1): Allow decomposing up to 16
nested components.  Prevent crash if there are no end points or
points.
(sfnt_read_cvar_table): Prevent assigning uninitialized values.
(sfnt_vary_simple_glyph): Update commentary.