Hi

This patch is another partial fix for PR 84521. This is adding a 
definition to one of the target hooks used in the SJLJ implemetation so 
that AArch64 defines the hard_frame_pointer_rtx as the 
TARGET_BUILTIN_SETJMP_FRAME_VALUE. As pointed out by Wilco there is 
still a lot more work to be done for these builtins in the future.

Testing: Bootstrapped and regtested on aarch64-none-linux-gnu and added 
new test.

Is this ok for trunk?

Sudi


*** gcc/ChangeLog ***

2018-03-14  Sudakshina Das  <sudi.das@arm.com>

	* builtins.c (expand_builtin_setjmp_receiver): Update condition
	to restore frame pointer.
	* config/aarch64/aarch64.h (DONT_USE_BUILTIN_SETJMP): Update
	comment.
	* config/aarch64/aarch64.c (aarch64_builtin_setjmp_frame_value):
	New.
	(TARGET_BUILTIN_SETJMP_FRAME_VALUE): Define.

*** gcc/testsuite/ChangeLog ***

2018-03-14  Sudakshina Das  <sudi.das@arm.com>

	* gcc.c-torture/execute/pr84521.c: New test.