* lib/gen-uni-tables.c (output_composition_tables): Add a filename2
parameter. Emit definitions of UNINORM_COMPOSE_MAX_ARG1 and
UNINORM_COMPOSE_MAX_ARG2 to this file.
(main): Invoke it with additional file name
uninorm/composition-table-bounds.h.
* uninorm/composition-table-bounds.h: New generated file.
* lib/uninorm/composition.c: Include it.
(uc_composition): Use UNINORM_COMPOSE_MAX_ARG1 and
UNINORM_COMPOSE_MAX_ARG2 instead of hardcoded bounds.