hppa64: Improve compatibility with HP ld on HP-UX

Provided symbols are revised to match those provided by HP ld.
This fixes startup issues caused by defining __FPU_MODEL,
__libdl_jmp_tbl and __systab.

This change adds the emultempl/hppa64elf.em file.  We now always
link against /lib/pa20_64/milli.a on HP-UX.

HP-UX shared libraries have some unresolved symbols.  So, we also
need to ignore unresolved symbols in shared libraries.

We adjust TEXT_START_ADDR and SHLIB_TEXT_START_ADDR to match the
values used by HP ld.

The .data section is moved to the start of the data segment.

2026-03-15  John David Anglin  <danglin@gcc.gnu.org>

ld/ChangeLog:

	* emulparams/elf64hppa.sh (TEXT_START_ADDR): Revise value to match
	HP ld value.
	(SHLIB_TEXT_START_ADDR): Likewise.
	(EXTRA_EM_FILE): Define.
	(OTHER_SYMBOLS): Revise to match symbols provided by HP ld.
	* emultempl/hppa64elf.em: New file.
	* scripttempl/elf64hppa.sc: Move .data to start of segment.