Fix #122551: Metal displays black screen on ATI/Intel GPUs

When using Metal backend on ATI/Intel GPUs the stencil buffer doesn't
contain the correct information, skipping diffuse and glossy PBR components.

Failing behavior was introduced by e97e06ea2c
This PR works around this by reverting the code when using ATI/Intel GPUs.
The root cause is somewhere the combination of stencil export support, clear
operations and subpass.

**TODO**

- [ ] Validate that this fixes the ATI issue as well

Pull Request: https://projects.blender.org/blender/blender/pulls/122993

source/blender/draw/engines/eevee_next/eevee_gbuffer.hh

@@ -161,6 +161,15 @@ struct GBuffer {
       header_tx.clear(uint4(0));
     }
 
+    /* Workaround a Metal bug that is only showing up on ATI/Intel GPUs. */
+    if (GPU_type_matches(
+            GPU_DEVICE_ATI | GPU_DEVICE_INTEL | GPU_DEVICE_INTEL_UHD, GPU_OS_MAC, GPU_DRIVER_ANY))
+    {
+      header_tx.clear(uint4(0));
+      GPU_framebuffer_bind(gbuffer_fb);
+      return;
+    }
+
     if (!GPU_stencil_export_support()) {
       /* Clearing custom load-store frame-buffers is invalid,
        * clear the stencil as a regular frame-buffer first. */