Improve CFF string (especially glyphname) lookup performance.

We do this by avoiding memory allocation and file I/O.  This is
Savannah patch #7104.

* src/cff/cfftypes.h: Include PS cmaps service and
FT_INTERNAL_POSTSCRIPT_HINTS_H.
(CFF_SubFontRec): Remove `num_local_subrs'.
(CFF_FontRec): Add `num_strings', `strings', and `string_pool'
fields.
Remove `string_index' and `num_global_subrs' fields.
Use real types instead of `void' for `pshinter' and `psnames' fields.

* src/cff/cffload.c: Don't include PS cmaps service.
(cff_index_get_pointers): Add `pool' parameter which allows to
insert an extra NUL character for each String INDEX entry.
(cff_index_get_name): Make it a local function.
(cff_index_get_string): New function.
(cff_subfont_load): Updated.
(cff_font_load): Initialize `num_strings', `strings', and
`string_pool' fields in the `CFF_FontRec' structure.
(cff_index_get_sid_string): Use `cff_index_get_string' instead of
`cff_index_get_name'.
(cff_font_done): Updated.

* src/cff/cffload.h: Don't include PS cmaps service.
(cff_index_get_string): Added.
(cff_index_get_sid_string): Updated.

* src/cff/cffobjs.c: Don't include PS cmaps service and
FT_INTERNAL_POSTSCRIPT_HINTS_H.
(cff_size_get_globals_funcs, cff_slot_init): Updated.
(cff_face_init): Follow `cff_index_get_name',
`cff_index_get_string', and `cff_index_get_sid_string' changes.

* src/cff/cffcmap.c (cff_sid_free_glyph_name): Removed.
(cff_sid_to_glyph_name): Use `cff_index_get_cid_string'.
(cff_cmap_unicode_init): Updated.

* src/cff/cffdrivr.c: Don't include PS cmap service.
(cff_get_glyph_name): Avoid unnecessary lookup for POSTSCRIPT_CMAPS
service.
(cff_get_glyph_name, cff_ps_get_font_info, cff_get_ros): Follow API
`cff_index_get_sid_string' change.
(cff_get_name_index): Use `cff_index_get_string' instead of
`cff_index_get_name'.

* src/cff/cffgload.c: Don't include FT_INTERNAL_POSTSCRIPT_HINTS_H.
(cff_decoder_init, cff_decoder_prepare): Updated.
8 files changed