t-m68hc11-gas (T_CPPFLAGS): Add _ctor and _dtor.

	* config/m68hc11/t-m68hc11-gas (T_CPPFLAGS): Add _ctor and _dtor.
	* config/m68hc11/larith.asm (_exit): Split in several sub-sections
	merged by linker script to get a final _exit().
	(__do_global_dtors): New for destructor handling in specific exit
	section.
	(__do_global_ctors): New for constructors in specific install section.
	(__map_data_section): Map data sections before running constructors.
	* config/m68hc11/m68hc11.h (INT_ASM_OP): Define to use .word.
	(CTORS_SECTION_ASM_OP): Define to put in readonly section.
	(DTORS_SECTION_ASM_OP): Likewise.
	(CTORS_SECTION_FUNCTION): Define to force a reference to
	__do_global_ctors.
	(DTORS_SECTION_FUNCTION): Likewise for __do_global_dtors.

From-SVN: r44611