[ELF] Support archive:file syntax in input section descriptions

Fixes https://bugs.llvm.org/show_bug.cgi?id=44450

https://sourceware.org/binutils/docs/ld/Input-Section-Basics.html#Input-Section-Basics
The following two rules are not implemented.

* `archive:` matches every file in the archive.
* `:file` matches a file not in an archive.

Reviewed By: grimar, ruiu

Differential Revision: https://reviews.llvm.org/D75100