bfd/

bfd/
	* elf-eh-frame.c (_bfd_elf_discard_section_eh_frame): Handle S flag.
	(_bfd_elf_write_section_eh_frame): Likewise.
gas/
	* dw2gencfi.c (struct fde_entry, struct cie_entry): Add signal_frame
	field.
	(CFI_signal_frame): Define.
	(cfi_pseudo_table): Add .cfi_signal_frame.
	(dot_cfi): Handle CFI_signal_frame.
	(output_cie): Handle cie->signal_frame.
	(select_cie_for_fde): Don't share CIE if signal_frame flag is
	different.  Copy signal_frame from FDE to newly created CIE.
	* doc/as.texinfo: Document .cfi_signal_frame.