We are going to extend this later on.
* include/freetype/internal/ftobjs.h (FT_Size_InternalRec): New
structure with a single field `module_data'.
* src/base/ftobjs.c (FT_New_Size): Allocate `internal' field of
`FT_Size' structure.
* src/cff/cffgload.c (cff_builder_init, cff_decoder_prepare): Use
`size->internal->module_data' instead of `size->internal'.
* src/cff/cffobjs.c (cff_size_done): Deallocate `module_data'.
(cff_size_init, cff_size_select, cff_size_request): Use
`size->internal->module_data' instead of `size->internal'.
* src/cif/cidobjs.c (cid_size_done, cid_size_init,
cid_size_request): Use `size->internal->module_data' instead of
`size->internal'.
* src/psaux/psobjs.c (t1_builder_ini): Use
`size->internal->module_data' instead of `size->internal'.
* src/type1/t1objs.c (T1_Size_Done, T1_Size_Init, T1_Size_Request):
Use `size->internal->module_data' instead of `size->internal'.