re PR target/82641 (Unable to enable crc32 for a certain function with target...

re PR target/82641 (Unable to enable crc32 for a certain function with target attribute on ARM (aarch32))

2017-11-17  Tamar Christina  <tamar.christina@arm.com>

	PR target/82641
	* config/arm/arm.c (arm_valid_target_attribute_rec):
	Parse "arch=" and "+<ext>".
	(arm_valid_target_attribute_tree): Re-init global options.
	(arm_option_override): Make non-static.
	(arm_options_perform_arch_sanity_checks): Make errors fatal.
	* gcc/config/arm/arm-c.c (__ARM_FEATURE_CMSE): Support undef.
	(__ARM_FEATURE_CRC32): Support undef.
	* config/arm/arm_acle.h (__ARM_FEATURE_CRC32): Replace with pragma.
	* doc/extend.texi (ARM Function Attributes): Add pragma and target.

gcc/testsuite/
2017-11-17  Tamar Christina  <tamar.christina@arm.com>

	PR target/82641
	* gcc.target/arm/pragma_arch_attribute.c: New.

From-SVN: r254878