Don't add PHDR for objcopy/strip or ld script specifying PHDRS

Don't add PHDR for objcopy/strip or ld script specifying PHDRS

HPPA64 needs to add a DT_PHDR header for shared libs.  That's fine
when linking but shouldn't happen for strip/objcopy.  Also PHDR must
come first so there's no need to look at all program headers.

bfd/
	* elf64-hppa.c (elf64_hppa_modify_segment_map): Don't add PHDR
	for objcopy/strip or when a ld script specifies PHDRS.
ld/
	* testsuite/ld-elf/nobits-1.d: Remove xfail for hppa64.
	* testsuite/ld-elf/note-1.d: Likewise.
	* testsuite/ld-elf/note-2.d: Likewise.