gdb/

gdb/
	* dwarf2expr.c (execute_stack_op): Support DW_OP_GNU_parameter_ref.
	* dwarf2loc.c (call_site_parameter_matches): Support
	CALL_SITE_PARAMETER_PARAM_OFFSET.
	(needs_dwarf_reg_entry_value): Push stub value.
	* dwarf2read.c (read_call_site_scope): New variable origin.  Support
	CALL_SITE_PARAMETER_PARAM_OFFSET and its DW_AT_abstract_origin.
	* gdbtypes.h (enum call_site_parameter_kind): New item
	CALL_SITE_PARAMETER_PARAM_OFFSET.
	(struct call_site.parameter.u): New field param_offset.

gdb/testsuite/
	* gdb.arch/amd64-entry-value-param.S: New file.
	* gdb.arch/amd64-entry-value-param.c: New file.
	* gdb.arch/amd64-entry-value-param.exp: New file.