fix(dx12): don't depend on BG{,L} entry order

This isn't guaranteed by `wgpu-core`; we should try to match by binding
slot index instead.

CHANGELOG.md

@@ -162,6 +162,10 @@ Bottom level categories:
 
 - Set object labels when the DEBUG flag is set, even if the VALIDATION flag is disabled. By @DJMcNab in [#5345](https://github.com/gfx-rs/wgpu/pull/5345).
 
+#### DX12
+
+- Don't depend on bind group and bind group layout entry order in HAL. This caused incorrect severely incorrect command execution and, in some cases, crashes. By @ErichDonGubler in [#5421](https://github.com/gfx-rs/wgpu/pull/5421).
+
 ## v0.19.3 (2024-03-01)
 
 This release includes `wgpu`, `wgpu-core`, and `wgpu-hal`. All other crates are unchanged.

wgpu-hal/src/dx12/device.rs

@@ -1100,7 +1100,16 @@ impl crate::Device for super::Device {
         }
         let mut dynamic_buffers = Vec::new();
 
-        for (layout, entry) in desc.layout.entries.iter().zip(desc.entries.iter()) {
+        let layout_and_entry_iter = desc.entries.iter().map(|entry| {
+            let layout = desc
+                .layout
+                .entries
+                .iter()
+                .find(|layout_entry| layout_entry.binding == entry.binding)
+                .expect("internal error: no layout entry found with binding slot");
+            (layout, entry)
+        });
+        for (layout, entry) in layout_and_entry_iter {
             match layout.ty {
                 wgt::BindingType::Buffer {
                     has_dynamic_offset: true,