Auto merge of #2274 - noproto:master, r=JohnTitor
Auto merge of #2274 - noproto:master, r=JohnTitor

Add dladdr1 for GNU/Linux platforms

Hey, this is my first pull request in a large open source project. Let me know if I'm missing anything or if you see any compile errors. This addresses dladdr1 missing in the libc library for GNU/Linux platforms.

rust-lang/libc,rust-lang/libc,rust-lang/libc