[smooth] Remove usage of setjmp and longjmp.
To support WASM targets with slow or unsupported setjmp and longjmp,
we eliminate these calls in favor of an error propagation model.
When gray_set_cell is out of cells, it raises an exception which is
later handled in gray_convert_glyph_inner.
This is a less invasive alternative to !385.
* src/smooth/ftgrays.c (gray_set_cell): Raise the overflow exception
and redirect all work to `cell_null`.
(gray_move,line,conic,cubic_to): Return the exception.
(gray_convert_glyph, gray_convert_glyph_inner): Handle the exception.
1 file changed
