LCC (Elbrus C Compiler) doesn't understand some of
GCC pragmas, despite of declaring itself GCC-aware.
The pragma of subject is the one that forbids vectorizing.
Actually, LCC don't vectorize anything unless explicitly
said to, so this pragma may be safely omitted and thus
not cause an error. This patch does this.
Our nightly and release binaries build in an environment that does not
support these instructions. Disable them everywhere for simplicity
because CMake's application of this library is not performance-critical.
Although the upstream has a CMake build system, it is meant for the
complete package. Add a simple one to build just the static library
we need within CMake.
