ld: Remove PF_X from PT_PHDR segment

ld: Remove PF_X from PT_PHDR segment

It was reasonable to mark PT_PHDR segment with PF_X for compatibility
with UnixWare and Solaris linkers 20 years ago.  But it is inappropriate
today when the primary OS of GNU ld is Linux.  This patch removes PF_X
from PT_PHDR segment as gold does.

Tested natively on Linux/x86 as well as crosss-binutils for alpha-linux,
ia64-linux, powerpc64-linux, powerpc-linux, s390-linux, s390x-linux,
sparc64-linux and sparc-linux.

bfd/

	PR ld/22423
	* elf.c (_bfd_elf_map_sections_to_segments): Remove PF_X from
	PT_PHDR segment.

ld/

	PR ld/22423
	* testsuite/ld-alpha/tlsbin.rd: Replace "R E " with "R +" for
	PT_PHDR segment.
	* testsuite/ld-alpha/tlsbinr.rd: Likewise.
	* testsuite/ld-ia64/tlsbin.rd: Likewise.
	* testsuite/ld-powerpc/tlsexe.r: Likewise.
	* testsuite/ld-powerpc/tlsexe32.r: Likewise.
	* testsuite/ld-powerpc/tlsexetoc.r: Likewise.
	* testsuite/ld-s390/tlsbin.rd: Likewise.
	* testsuite/ld-s390/tlsbin_64.rd: Likewise.
	* testsuite/ld-sparc/tlssunbin32.rd: Likewise.
	* testsuite/ld-sparc/tlssunbin64.rd: Likewise.
	* testsuite/ld-elf/pr22423.d: New test.