[CodeGen] add remquo to list of recognized library calls

This is just an oversight because we already do recognize __builtin_remquo()
with the same signature.

http://en.cppreference.com/w/c/numeric/math/remquo
http://pubs.opengroup.org/onlinepubs/9699919799/functions/remquo.html

Differential Revision: https://reviews.llvm.org/D39615

llvm-svn: 317407