invoke.texi: Document -mlong-calls for 68HC12.

invoke.texi: Document -mlong-calls for 68HC12.

	* doc/invoke.texi: Document -mlong-calls for 68HC12.

	* config/m68hc11/m68hc11.h (CPP_SPEC): Pass -D__USE_RTC__ when
	-mlong-calls is specified.
	(ASM_DECLARE_FUNCTION_NAME): Define to generate .far and .interrupt
	assembler directives.
	(TARGET_LONG_CALL, MASK_LONG_CALL): Declare.
	(TARGET_SWITCHES): Add -mlong-calls options.
	(current_function_far): Declare.

	* config/m68hc11/m68hc11.c (m68hc11_initial_elimination_offset): Take
	into account the page register saved on the stack.
	(m68hc11_override_options): Take into account -mlong-calls option.
	(m68hc11_asm_file_start): Put a mode for the ELF flags ABI.

	* config/m68hc11/m68hc11.md ("*return_32bit"): Return rtc
	if the function is going to be in 68HC12 banked memory (-mlong-calls).
	("*return_16bit"): Likewise.
	("*return_void"): Likewise.
	("call", "call_value"): Use call for a far function call.

From-SVN: r56275