glsl_compiler: Add binding hash tables to avoid SIGSEVs on linking stage

glsl_compiler: Add binding hash tables to avoid SIGSEVs on linking stage

When using the stand alone compiler, if we try to link a shader with vertex
attributes it will segfault on linking as the binding hash tables are not
included in the shader program. Obviously, we cannot make the linking stage
succeed without the bound attributes but we can prevent the crash and just
let the linker spit its own error.

Reviewed-by: Brian Paul <brianp@vmware.com>