compiler: introduce a libcompiler static library

compiler: introduce a libcompiler static library

Currently it's an empty library, although it'll be used to store common
code between GLSL and NIR that is compiler specific (rather than generic
as the one in src/util).

XXX: strictly speaking we could add a python/mako parser to generate the
relevant files instead including builtin_type_macros.h in such a manner.

Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Acked-by: Matt Turner <mattst88@gmail.com>
Acked-by: Jose Fonseca <jfonseca@vmware.com>