[AArch64] Add spellchecking hints for -march,-mcpu,-mtune and their attributes

[AArch64] Add spellchecking hints for -march,-mcpu,-mtune and their attributes

	* config/aarch64/aarch64.c (aarch64_print_hint_for_core_or_arch):
	New function.
	(aarch64_print_hint_for_core): Likewise.
	(aarch64_print_hint_for_arch): Likewise.
	(aarch64_validate_march): Use it.  Fix indentation in type signature.
	(aarch64_validate_mcpu): Use aarch64_print_hint_for_core_or_arch.
	(aarch64_validate_mtune): Likewise.
	(aarch64_handle_attr_arch): Likewise.
	(aarch64_handle_attr_cpu): Likewise.
	(aarch64_handle_attr_tune): Likewise.

	* gcc.target/aarch64/spellcheck_1.c: New test.
	* gcc.target/aarch64/spellcheck_2.c: Likewise.
	* gcc.target/aarch64/spellcheck_3.c: Likewise.
	* gcc.target/aarch64/spellcheck_4.c: Likewise.
	* gcc.target/aarch64/spellcheck_5.c: Likewise.
	* gcc.target/aarch64/spellcheck_6.c: Likewise.

From-SVN: r241149