PR 33452 SEGV in bfd_elf_gc_record_vtentry

Limit addends on vtentry relocs, otherwise ld might attempt to
allocate a stupidly large array.  This also fixes the expression
overflow leading to pr33452.  A vtable of 33M entries on a 64-bit
host is surely large enough, especially considering that VTINHERIT
and VTENTRY relocations are to support -fvtable-gc that disappeared
from gcc over 20 years ago.

	PR ld/33452
	* elflink.c (bfd_elf_gc_record_vtentry): Sanity check addend.