search for: r128769

Hi, I'd like to link Clang against the STP theorem prover. Since Clang is built by the LLVM build system, I hope this is the correct place to ask for advice. The attached patch allows me to pass `configure` a --with-stp option and provide a path to the install prefix for STP. However, I am not familiar with autoconf, so I am not confident that my changes are the correct way to do this. I