unwind-dw2-fde-glibc.c (base_from_cb_data, [...]): Use gcc_assert and gcc_unreachable as appropriate.

	* unwind-dw2-fde-glibc.c (base_from_cb_data,
	_Unwind_IteratePhdrCallback): Use gcc_assert and gcc_unreachable as
	appropriate.
	* unwind-dw2-fde.c (__deregister_frame_info_bases,
	base_from_object, fde_split, end_fde_sort): Likewise.
	* unwind-dw2.c (_Unwind_GetGR, _Unwind_SetGR, execute_stack_op,
	execute_cfa_program, _Unwind_SetSpColumn, uw_update_context_1,
	uw_init_context_1): Likewise.
	* unwind.inc (_Unwind_RaiseException_Phase2, _Unwind_Resume,
	_Unwind_Resume_or_Rethrow): Likewise.
	* unwind-pe.h (__gxx_abort): Do not define.
	(size_of_encoded_value, base_of_encoded_value,
	read_encoded_value_with_base): Use gcc_unreachable.
	* unwind.h (_Unwind_GetTextRelBase): Likewise.

From-SVN: r99835