Static checking by Sun C 5.12.

Static checking by Sun C 5.12.

* lib-src/etags.c (analyse_regex): Omit unreachable code.
* src/alloc.c (buffer_memory_full) [REL_ALLOC]:
* src/bytecode.c (exec_byte_code):
* src/dispnew.c (init_display):
* src/eval.c (error):
* src/fileio.c (Fsubstitute_in_file_name):
* src/keyboard.c (Fevent_convert_list):
* src/keymap.c (Fsingle_key_description):
* src/term.c (maybe_fatal, fatal):
* src/xfns.c (Fx_display_backing_store, Fx_display_visual_class):
* src/xsmfns.c (Fhandle_save_session):
Omit unreachable code.
* src/keymap.c (map_keymap_char_table_item): Cast void * to
a function pointer type; the C Standard requires this.