intel/debug: Add a common INTEL_DEBUG=nohiz option

The GL driver had a driconf option (which doesn't make much sense) and
the Vulkan driver had a hand-rolled environment variable.  Instead,
let's tie both into the INTEL_DEBUG mechanism and unify things.

Reviewed-by: Topi Pohjolainen <topi.pohjolainen@intel.com>

src/intel/common/gen_debug.c

@@ -82,6 +82,7 @@ static const struct debug_control debug_control[] = {
    { "l3",          DEBUG_L3 },
    { "do32",        DEBUG_DO32 },
    { "norbc",       DEBUG_NO_RBC },
+   { "nohiz",       DEBUG_NO_HIZ },
    { NULL,    0 }
 };
 

src/intel/common/gen_debug.h

@@ -78,6 +78,7 @@ extern uint64_t INTEL_DEBUG;
 #define DEBUG_L3                  (1ull << 36)
 #define DEBUG_DO32                (1ull << 37)
 #define DEBUG_NO_RBC              (1ull << 38)
+#define DEBUG_NO_HIZ              (1ull << 39)
 
 #ifdef HAVE_ANDROID_PLATFORM
 #define LOG_TAG "INTEL-MESA"

src/intel/vulkan/anv_image.c

@@ -198,7 +198,7 @@ make_surface(const struct anv_device *dev,
          anv_perf_warn("Implement multi-arrayLayer HiZ clears and resolves");
       } else if (dev->info.gen == 8 && vk_info->samples > 1) {
          anv_perf_warn("Enable gen8 multisampled HiZ");
-      } else if (env_var_as_boolean("INTEL_VK_HIZ", true)) {
+      } else if (!unlikely(INTEL_DEBUG & DEBUG_NO_HIZ)) {
          assert(image->aux_surface.isl.size == 0);
          ok = isl_surf_get_hiz_surf(&dev->isl_dev, &image->depth_surface.isl,
                                     &image->aux_surface.isl);

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

@@ -880,7 +880,7 @@ brw_process_driconf_options(struct brw_context *brw)
       break;
    }
 
-   if (!driQueryOptionb(options, "hiz")) {
+   if (INTEL_DEBUG & DEBUG_NO_HIZ) {
        brw->has_hiz = false;
        /* On gen6, you can only do separate stencil with HIZ. */
        if (brw->gen == 6)

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

@@ -56,10 +56,6 @@ DRI_CONF_BEGIN
 	    DRI_CONF_ENUM(1, "Enable reuse of all sizes of buffer objects")
 	 DRI_CONF_DESC_END
       DRI_CONF_OPT_END
-
-      DRI_CONF_OPT_BEGIN_B(hiz, "true")
-	 DRI_CONF_DESC(en, "Enable Hierarchical Z on gen6+")
-      DRI_CONF_OPT_END
    DRI_CONF_SECTION_END
 
    DRI_CONF_SECTION_QUALITY