Extend the description of PE header flags.

Extend the description of PE header flags.

	PR 27760
include	* coff/pe.h (IMAGE_DLLCHARACTERISTICS_APPCONTAINER): Define.
	(IMAGE_DLLCHARACTERISTICS_GUARD_CF): Define.

bfd	* peXXigen.c (_bfd_XX_print_private_bfd_data_common): Add display
	of IMAGE_FILE_REMOVABLE_RUN_FROM_SWAP,
	IMAGE_FILE_NET_RUN_FROM_SWAP and IMAGE_FILE_UP_SYSTEM_ONLY flags.
	Decode the contents of the DllCharacteristics field.