m68hc11.c (m68hc11_emit_libcall): Use gcc_assert and gcc_unreachable as appropriate.

m68hc11.c (m68hc11_emit_libcall): Use gcc_assert and gcc_unreachable as appropriate.

	* config/m68hc11/m68hc11.c (m68hc11_emit_libcall): Use gcc_assert
	and gcc_unreachable as appropriate.
	(expand_prologue, expand_epilogue, m68hc11_gen_lowpart,
	m68hc11_gen_highpart, print_operand, print_operand_address,
	m68hc11_expand_compare, m68hc11_expand_compare_and_branch,
	m68hc11_gen_movhi): Likewise.
	* config/m68hc11/m68hc11.h (HARD_X_REGNUM): Reword comment.
	* config/m68hc11/m68hc11.md: Reword comment.

From-SVN: r99407