glsl: rename gl_nir_link() to gl_nir_link_spirv()

A NIR based glsl linking function will be too different to the
spirv version to bother attempting any sharing. So lets change
the name to be explicit.

Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>

src/compiler/glsl/gl_nir_linker.c

@@ -567,8 +567,8 @@ nir_build_program_resource_list(struct gl_context *ctx,
 }
 
 bool
-gl_nir_link(struct gl_context *ctx, struct gl_shader_program *prog,
-            const struct gl_nir_linker_options *options)
+gl_nir_link_spirv(struct gl_context *ctx, struct gl_shader_program *prog,
+                  const struct gl_nir_linker_options *options)
 {
    if (!gl_nir_link_uniform_blocks(ctx, prog))
       return false;