PR30343, LTO ignores linker reference to _pei386_runtime_relocator

PR30343, LTO ignores linker reference to _pei386_runtime_relocator

Make a reference to _pei386_runtime_relocator before LTO recompilation.
This is done regardless of whether such a reference will be used,
because it can't be known whether it is needed before LTO.

I also found it necessary to enable long section names for the bfd
created in make_runtime_pseudo_reloc, because otherwise when writing
it out to the bfd-in-memory we get the section written as .rdata_r
which when read back in leads to a linker warning ".rdata_r: section
below image base" and likely runtime misbehaviour.

	PR 30343
	* emultempl/pe.em (make_runtime_ref): New function.
	(gld${EMULATION_NAME}_before_plugin_all_symbols_read): New function.
	(LDEMUL_BEFORE_PLUGIN_ALL_SYMBOLS_READ): Define.
	* emultempl/pep.em: Similarly to pe.em.
	* pe-dll.c (make_runtime_pseudo_reloc): Set long section names.