i965: Enable disk shader cache by default

Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
Reviewed-by: Tapani Pälli <tapani.palli@intel.com>
Acked-by: Kenneth Graunke <kenneth@whitecape.org>

docs/relnotes/18.1.0.html

@@ -47,6 +47,7 @@ Note: some of the new features are only available with certain drivers.
 <li>GL_ARB_bindless_texture on nvc0/maxwell+</li>
 <li>GL_EXT_semaphore on radeonsi</li>
 <li>GL_EXT_semaphore_fd on radeonsi</li>
+<li>Disk shader cache support for i965 enabled by default</li>
 </ul>
 
 <h2>Bug fixes</h2>

src/mesa/drivers/dri/i965/brw_disk_cache.c

@@ -407,9 +407,6 @@ void
 brw_disk_cache_init(struct intel_screen *screen)
 {
 #ifdef ENABLE_SHADER_CACHE
-   if (env_var_as_boolean("MESA_GLSL_CACHE_DISABLE", true))
-      return;
-
    char renderer[10];
    MAYBE_UNUSED int len = snprintf(renderer, sizeof(renderer), "i965_%04x",
                                    screen->deviceID);