Bug#819072: fixed in llvm-toolchain-3.8 1:3.8.1~+rc1-1~exp1

[antoine.pierlot-garcin at scle.fr]

Dear maintainer,

When using llvm-3.8-dev  1:3.8.1~+rc1-1~exp1, the bug is still not
completely fixed.

/usr/lib/llvm-3.8/share/llvm/cmake/LLVMExports.cmake still detects the
missing installation of the following library files:

     "/usr/lib/llvm-3.8/lib/libPollyISL.a"
     "/usr/lib/llvm-3.8/lib/libPolly.a"
     "/usr/lib/llvm-3.8/bin/sancov"

(Similar to section 3 of Brad King's message #20 at
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=819072#20 )

The first two are deleted during packaging, and the third one is
installed by clang-3.8, which is not a dependency of llvm-3.8-dev.

After commenting `libPolly*.a` checks from
`LLVMExports-relwithdebinfo.cmake` and installing clang-3.8,
`find_package(LLVM)` works fine.

Thanks,
Antoine