blade: tune belt alignment to match Intel Iris Xe

crates/gpui/src/platform/linux/blade_atlas.rs

@@ -58,7 +58,7 @@ impl BladeAtlas {
             upload_belt: BladeBelt::new(BladeBeltDescriptor {
                 memory: gpu::Memory::Upload,
                 min_chunk_size: 0x10000,
-                alignment: 4,
+                alignment: 64, // Vulkan `optimalBufferCopyOffsetAlignment` on Intel XE
             }),
             monochrome_textures: Default::default(),
             polychrome_textures: Default::default(),

crates/gpui/src/platform/linux/blade_renderer.rs

@@ -251,7 +251,7 @@ impl BladeRenderer {
         let instance_belt = BladeBelt::new(BladeBeltDescriptor {
             memory: gpu::Memory::Shared,
             min_chunk_size: 0x1000,
-            alignment: 0x100, // required by DX12
+            alignment: 0x40, // Vulkan `minStorageBufferOffsetAlignment` on Intel Xe
         });
         let atlas = Arc::new(BladeAtlas::new(&gpu));
         let atlas_sampler = gpu.create_sampler(gpu::SamplerDesc {