PR27567, Linking PE files adds alignment section flags to executables

PR27567, Linking PE files adds alignment section flags to executables

So don't set those flags for an executable.  In the patch I also test
DYNAMIC even though the PE bfd code doesn't appear to set it for dlls.
I figure it doesn't hurt to include that flag too.

	PR 27567
bfd/
	* coffcode.h (styp_to_sec_flags): Use an unsigned long styp_flags.
	(coff_write_object_contents): Pass bfd to COFF_ENCODE_ALIGNMENT,
	ignore alignment checks when return is false.  Formatting.
include/
	* coff/internal.h (struct internal_scnhdr): Make s_flags unsigned long.
	* coff/pe.h (COFF_ENCODE_ALIGNMENT): Don't set align flags for an
	executable and return false.  Do so for a relocatable object and
	evaluate to true.
	* coff/ti.h (COFF_ENCODE_ALIGNMENT): Add bfd arg and evaluate to true.
	(COFF_DECODE_ALIGNMENT): Formatting.
	* coff/z80.h (COFF_ENCODE_ALIGNMENT): Similarly.
	(COFF_DECODE_ALIGNMENT): Similarly.