bfd/

	bfd/
	* elf32-arm.c (elf32_arm_howto_table_1): Change offset for
	R_THM_CALL to 25 and remove FIXME comment.
	(using_thumb2): New function.
	(elf32_arm_final_link_relocate): Cope with Thumb-2 BL encoding.

	include/
	* elf/arm.h: Define TAG_CPU_ARCH_* constants.

	ld/testsuite/
	* ld-arm/arm-elf.exp: Add thumb1-bl, thumb2-bl,
	thumb2-bl-as-thumb1-bad and thumb2-bl-bad tests.
	* ld-arm/thumb1-bl.d: New.
	* ld-arm/thumb1-bl.s: New.
	* ld-arm/thumb2-bl-as-thumb1-bad.d: New.
	* ld-arm/thumb2-bl-as-thumb1-bad.s: New.
	* ld-arm/thumb2-bl-bad.d: New.
	* ld-arm/thumb2-bl-bad.s: New.
	* ld-arm/thumb2-bl.d: New.
	* ld-arm/thumb2-bl.s: New.