Hi

This patch is part of a series of patches to add support for Armv8.1-M 
Mainline instructions to binutils.

This patch adds the BF instruction.

Testing: Added new tests for the valid instructions operands. Testsuite 
shows no regression when run for arm-none-eabi targets.

Thanks
Sudi


ChangeLog entries are as follows :

*** gas/ChangeLog ***

2019-04-04  Sudakshina Das  <sudi.das@arm.com>

	* config/tc-arm.c (T16_32_TAB): New entries for bf.
	(do_t_branch_future): New.
	(insns): New instruction for bf.
	* testsuite/gas/arm/armv8_1-m-bf.d: New.
	* testsuite/gas/arm/armv8_1-m-bf.s: New.
	* testsuite/gas/arm/armv8_1-m-bf-bad.s: New
	* testsuite/gas/arm/armv8_1-m-bf-bad.l: New
	* testsuite/gas/arm/armv8_1-m-bf-bad.d: New

*** ld/ChangeLog ***

2019-04-04  Sudakshina Das  <sudi.das@arm.com>

	* testsuite/ld-arm/bf.s: New.
	* testsuite/ld-arm/bf.d: New.
	* testsuite/ld-arm/arm-elf.exp: Add above test.

*** opcodes/ChangeLog ***

2019-04-04  Sudakshina Das  <sudi.das@arm.com>

	* arm-dis.c (thumb32_opcodes): New instructions for bf.