[AArch64][PR target/84882] Add mno-strict-align

[AArch64][PR target/84882] Add mno-strict-align

*** gcc/ChangeLog ***

2018-05-23  Sudakshina Das  <sudi.das@arm.com>

	PR target/84882
	* common/config/aarch64/aarch64-common.c (aarch64_handle_option):
	Check val before adding MASK_STRICT_ALIGN to opts->x_target_flags.
	* config/aarch64/aarch64.opt (mstrict-align): Remove RejectNegative.
	* config/aarch64/aarch64.c (aarch64_attributes): Mark allow_neg
	as true for strict-align.
	(aarch64_can_inline_p): Perform checks even when callee has no
	attributes to check for strict alignment.
	* doc/extend.texi (AArch64 Function Attributes): Document
	no-strict-align.
	* doc/invoke.texi: (AArch64 Options): Likewise.

*** gcc/testsuite/ChangeLog ***

2018-05-23  Sudakshina Das  <sudi.das@arm.com>

	PR target/84882
	* gcc.target/aarch64/pr84882.c: New test.
	* gcc.target/aarch64/target_attr_18.c: Likewise.

From-SVN: r260604