glsl: use the linear allocator in opt_dead_code_local
glsl: use the linear allocator in opt_dead_code_local

Tested-by: Edmondo Tommasina <9e91d6b21d26a489d8e8a656718247cfcec7b511@gmail.com>
Reviewed-by: Nicolai Hähnle <0d0be6cf5ad662651be2dc5dfd44aa2b09d4c1cc@amd.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler