[PR ld/22269] aarch64: Handle local undefined weak symbols

[PR ld/22269] aarch64: Handle local undefined weak symbols

With static pie linking undefined weak symbols are forced to resolve locally
to 0, so no GOT setup is needed in elfNN_aarch64_finish_dynamic_symbol,
which previously failed for these symbols.

The failure caused the unhelpful error message:
"ld: final link failed: Nonrepresentable section on output"

bfd/
	PR ld/22269
	* elfnn-aarch64.c (elfNN_aarch64_finish_dynamic_symbol): Use
	UNDEFWEAK_NO_DYNAMIC_RELOC to avoid dynamic GOT relocs.
	(elfNN_aarch64_allocate_dynrelocs): Likewise.