Find local llvm-config first

Distro's llvm usually have a 6.0 suffix.Any custom llvm build
names the binary as llvm-config.Keeping 6.0 variant first causes
the distro's llvm to be compiled in place of a custom one even if
given using CMAKE_PREFIX_PATH.
6e55f61581prazzb committed on 8/13/2018, 5:25:19 PMparent6549712
1 file changedLine totals unavailable