Warning fixes.

	Warning fixes.
	* ada-lang.c (find_struct_field): Initialize *byte_offset_p.
	* breakpoint.c (do_enable_breakpoint): Ignore both mem_cnt and i.
	* c-typeprint.c (c_type_print_varspec_suffix): Don't test length
	greater than or equal to zero.
	* m2-typeprint.c (m2_array): Likewise.
	* p-typeprint.c (pascal_type_print_varspec_prefix): Likewise.
	* gdbtypes.c (copy_type_recursive): Correct == typo.
	* i386-tdep.c (i386_skip_prologue): Remove stray semicolon.
	* linux-nat.c (linux_nat_info_proc_cmd): Don't compare a pointer
	greater than zero.
	* macroscope.c (sal_macro_scope): Don't name a local variable "main".
	(default_macro_scope): Remove unused variable.
	* prologue-value.h (pv_area_find_reg): Don't name an argument
	"register".
	* remote-fileio.c (remote_fio_func_map): Add missing braces.
	* remote.c (sigint_remote_twice_token, sigint_remote_token): Change
	type.
	(cleanup_sigint_signal_handler): Remove casts.
	* valprint.c (val_print): Use a volatile local for the modified
	argument.
	* varobj.c (languages): Remove extra array dimension.
	(varobj_create): Correct access to languages array.
	* mi/mi-cmd-break.c (mi_cmd_break_insert, mi_cmd_break_watch): Add
	missing braces.
	* mi/mi-cmd-disas.c (mi_cmd_disassemble): Likewise.
	* mi/mi-cmd-env.c (mi_cmd_env_path, mi_cmd_env_dir): Likewise.
	* mi/mi-getopt.c (mi_valid_noargs): Likewise.
	* mi/mi-main.c (mi_cmd_data_read_memory): Likewise.
	(mi_cmd_data_write_memory): Likewise.
	* signals/signals.c (target_signal_to_string): Cast to int before
	comparing.
	* tui/tui-layout.c (init_and_make_win): Take and return a void *.
	Update all callers.