LLVM Clang 3.9.1, Clang 4.0 & GCC 6.3 With Intel's Clear Linux

Clang 4.0 does enough with TSCP to allow it to come out ahead of GCC 6.

GraphicsMagick does see some performance boosts when built by Clang 4.0, but still wasn't enough to beat GCC for this OpenMP-heavy workload.

Clang has seen some slowdowns in compile times recently but good to see it's back to getting on track compared to GCC.