Support Solaris symbol filtering in self-hosted ELF linker

[alexrp]

https://docs.oracle.com/cd/E36784_01/html/E36857/chapter4-4.html

I don't know how this stuff is even supposed to work, but it's been observed that Solaris/illumos executables created with the self-hosted linker end up with call 0x0 instructions for calls that should go to a filtered symbol, e.g. dl_iterate_phdr which should be redirected from libc.so to ld.so.