Install three utils, "FileCheck", "count", and "not", for now to appease llvmlab dragonegg builder.

Since r197684, "install/bin/llvm-config --obj-root" hasn't shown the build tree. The builder was finding utils in the build tree, from the installed tree.

I will revert this after dragonegg builder would be tweaked not to use installed llvm-config.

llvm-svn: 197786