gdb

gdb
	* frame.h (frame_unwinder_is): Declare.
	* frame.c (frame_unwinder_is): New function.
	* dwarf2loc.c: Include dwarf2-frame.h.
	(dwarf_expr_frame_cfa): New function.
	(dwarf2_evaluate_loc_desc): Use it.
	(needs_frame_frame_cfa): New function.
	(dwarf2_loc_desc_needs_frame): Use it.
	* dwarf2expr.h (struct dwarf_expr_context) <get_frame_cfa>: New
	field.
	* dwarf2expr.c (execute_stack_op) <DW_OP_call_frame_cfa>: New
	case.
	* dwarf2-frame.h (dwarf2_frame_cfa): Declare.
	* dwarf2-frame.c (no_get_frame_cfa): New function.
	(execute_stack_op): Use it.
	(dwarf2_frame_cfa): New function.
gdb/testsuite
	* gdb.dwarf2/callframecfa.exp: New file.
	* gdb.dwarf2/callframecfa.S: New file.