* Make-common.in (SIM_ENVIRONMENT): New variable.

	* Make-common.in (SIM_ENVIRONMENT): New variable.
	(CONFIG_CFLAGS): Add it.
	* aclocal.m4 (SIM_AC_OPTION_ENVIRONMENT): Handle
	--enable-sim-environment option.
	* configure: Regenerated.
	* sim-config.h (environment support): Rewrite.
	* sim-config.c (current_environment): Define as enum, unconditionally.
	(current_alignment): Define unconditionally.
	(config_environment_to_a): Update.
	(config_alignment_to_a): Fix type of argument.  Define unconditionally.
	(sim_config): Handle environment and alignment determination
	unconditionally.  Delete sanity checks of current_environment,
	unnecessary.
	(print_sim_config): Update.
	* sim-options.c (STANDARD_OPTIONS enum): Add OPTION_ENVIRONMENT.
	(standard_options): Add --environment.
	(standard_option_handler): Likewise.