glsl: replace old hash table with new and faster one
glsl: replace old hash table with new and faster one

The util/hash_table was intended to be a fast hash table
replacement for the program/hash_table see 35fd61bd99c1 and
72e55bb6888ff.

Reviewed-by: Timothy Arceri <7f85c8176b2576ffafd04ac63cd29ed35ff86cb6@yahoo.com.au>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler