Handling ARMv8-M Security Extension's cmse_nonsecure_call attribute

Handling ARMv8-M Security Extension's cmse_nonsecure_call attribute

    gcc/ChangeLog:
    2016-12-02  Andre Vieira  <andre.simoesdiasvieira@arm.com>
	        Thomas Preud'homme  <thomas.preudhomme@arm.com>

	* config/arm/arm.c (gimplify.h): New include.
	(arm_handle_cmse_nonsecure_call): New.
	(arm_attribute_table): Added cmse_nonsecure_call.
	(arm_comp_type_attributes): Deny compatibility of function types
	with without the cmse_nonsecure_call attribute.
	* doc/extend.texi (ARM ARMv8-M Security Extensions): New attribute.

    gcc/testsuite/ChangeLog:
    2016-12-02  Andre Vieira  <andre.simoesdiasvieira@arm.com>
	        Thomas Preud'homme  <thomas.preudhomme@arm.com>

	* gcc.target/arm/cmse/cmse-3.c: Add tests.
	* gcc.target/arm/cmse/cmse-4.c: Add tests.
	* gcc.target/arm/cmse/cmse-15.c: New.

Co-Authored-By: Thomas Preud'homme <thomas.preudhomme@arm.com>
From-SVN: r243191