Assorted updates:

 - Remove the return value from PopErrorScope (validation errors now
   cause promise rejection and not JS errors).
 - Add more mapping failure reasons to help browsers produce nice
   validation error messages.
 - Remove the unused WGPUTextureComponentType
 - Tag the buffer in SetVertexBuffer as nullable (to unset it).

webgpu.h

@@ -149,11 +149,14 @@ typedef enum WGPUBufferBindingType {
 
 typedef enum WGPUBufferMapAsyncStatus {
     WGPUBufferMapAsyncStatus_Success = 0x00000000,
-    WGPUBufferMapAsyncStatus_Error = 0x00000001,
+    WGPUBufferMapAsyncStatus_ValidationError = 0x00000001,
     WGPUBufferMapAsyncStatus_Unknown = 0x00000002,
     WGPUBufferMapAsyncStatus_DeviceLost = 0x00000003,
     WGPUBufferMapAsyncStatus_DestroyedBeforeCallback = 0x00000004,
     WGPUBufferMapAsyncStatus_UnmappedBeforeCallback = 0x00000005,
+    WGPUBufferMapAsyncStatus_MappingAlreadyPending = 0x00000006,
+    WGPUBufferMapAsyncStatus_OffsetOutOfRange = 0x00000007,
+    WGPUBufferMapAsyncStatus_SizeOutOfRange = 0x00000008,
     WGPUBufferMapAsyncStatus_Force32 = 0x7FFFFFFF
 } WGPUBufferMapAsyncStatus;
 
@@ -410,14 +413,6 @@ typedef enum WGPUTextureAspect {
     WGPUTextureAspect_Force32 = 0x7FFFFFFF
 } WGPUTextureAspect;
 
-typedef enum WGPUTextureComponentType {
-    WGPUTextureComponentType_Float = 0x00000000,
-    WGPUTextureComponentType_Sint = 0x00000001,
-    WGPUTextureComponentType_Uint = 0x00000002,
-    WGPUTextureComponentType_DepthComparison = 0x00000003,
-    WGPUTextureComponentType_Force32 = 0x7FFFFFFF
-} WGPUTextureComponentType;
-
 typedef enum WGPUTextureDimension {
     WGPUTextureDimension_1D = 0x00000000,
     WGPUTextureDimension_2D = 0x00000001,
@@ -1312,7 +1307,7 @@ typedef size_t (*WGPUProcDeviceEnumerateFeatures)(WGPUDevice device, WGPUFeature
 typedef bool (*WGPUProcDeviceGetLimits)(WGPUDevice device, WGPUSupportedLimits * limits);
 typedef WGPUQueue (*WGPUProcDeviceGetQueue)(WGPUDevice device);
 typedef bool (*WGPUProcDeviceHasFeature)(WGPUDevice device, WGPUFeatureName feature);
-typedef bool (*WGPUProcDevicePopErrorScope)(WGPUDevice device, WGPUErrorCallback callback, void * userdata);
+typedef void (*WGPUProcDevicePopErrorScope)(WGPUDevice device, WGPUErrorCallback callback, void * userdata);
 typedef void (*WGPUProcDevicePushErrorScope)(WGPUDevice device, WGPUErrorFilter filter);
 typedef void (*WGPUProcDeviceSetDeviceLostCallback)(WGPUDevice device, WGPUDeviceLostCallback callback, void * userdata);
 typedef void (*WGPUProcDeviceSetLabel)(WGPUDevice device, char const * label);
@@ -1352,7 +1347,7 @@ typedef void (*WGPUProcRenderBundleEncoderSetBindGroup)(WGPURenderBundleEncoder
 typedef void (*WGPUProcRenderBundleEncoderSetIndexBuffer)(WGPURenderBundleEncoder renderBundleEncoder, WGPUBuffer buffer, WGPUIndexFormat format, uint64_t offset, uint64_t size);
 typedef void (*WGPUProcRenderBundleEncoderSetLabel)(WGPURenderBundleEncoder renderBundleEncoder, char const * label);
 typedef void (*WGPUProcRenderBundleEncoderSetPipeline)(WGPURenderBundleEncoder renderBundleEncoder, WGPURenderPipeline pipeline);
-typedef void (*WGPUProcRenderBundleEncoderSetVertexBuffer)(WGPURenderBundleEncoder renderBundleEncoder, uint32_t slot, WGPUBuffer buffer, uint64_t offset, uint64_t size);
+typedef void (*WGPUProcRenderBundleEncoderSetVertexBuffer)(WGPURenderBundleEncoder renderBundleEncoder, uint32_t slot, WGPUBuffer buffer /* nullable */, uint64_t offset, uint64_t size);
 
 // Procs of RenderPassEncoder
 typedef void (*WGPUProcRenderPassEncoderBeginOcclusionQuery)(WGPURenderPassEncoder renderPassEncoder, uint32_t queryIndex);
@@ -1375,7 +1370,7 @@ typedef void (*WGPUProcRenderPassEncoderSetLabel)(WGPURenderPassEncoder renderPa
 typedef void (*WGPUProcRenderPassEncoderSetPipeline)(WGPURenderPassEncoder renderPassEncoder, WGPURenderPipeline pipeline);
 typedef void (*WGPUProcRenderPassEncoderSetScissorRect)(WGPURenderPassEncoder renderPassEncoder, uint32_t x, uint32_t y, uint32_t width, uint32_t height);
 typedef void (*WGPUProcRenderPassEncoderSetStencilReference)(WGPURenderPassEncoder renderPassEncoder, uint32_t reference);
-typedef void (*WGPUProcRenderPassEncoderSetVertexBuffer)(WGPURenderPassEncoder renderPassEncoder, uint32_t slot, WGPUBuffer buffer, uint64_t offset, uint64_t size);
+typedef void (*WGPUProcRenderPassEncoderSetVertexBuffer)(WGPURenderPassEncoder renderPassEncoder, uint32_t slot, WGPUBuffer buffer /* nullable */, uint64_t offset, uint64_t size);
 typedef void (*WGPUProcRenderPassEncoderSetViewport)(WGPURenderPassEncoder renderPassEncoder, float x, float y, float width, float height, float minDepth, float maxDepth);
 
 // Procs of RenderPipeline
@@ -1500,7 +1495,7 @@ WGPU_EXPORT size_t wgpuDeviceEnumerateFeatures(WGPUDevice device, WGPUFeatureNam
 WGPU_EXPORT bool wgpuDeviceGetLimits(WGPUDevice device, WGPUSupportedLimits * limits);
 WGPU_EXPORT WGPUQueue wgpuDeviceGetQueue(WGPUDevice device);
 WGPU_EXPORT bool wgpuDeviceHasFeature(WGPUDevice device, WGPUFeatureName feature);
-WGPU_EXPORT bool wgpuDevicePopErrorScope(WGPUDevice device, WGPUErrorCallback callback, void * userdata);
+WGPU_EXPORT void wgpuDevicePopErrorScope(WGPUDevice device, WGPUErrorCallback callback, void * userdata);
 WGPU_EXPORT void wgpuDevicePushErrorScope(WGPUDevice device, WGPUErrorFilter filter);
 WGPU_EXPORT void wgpuDeviceSetDeviceLostCallback(WGPUDevice device, WGPUDeviceLostCallback callback, void * userdata);
 WGPU_EXPORT void wgpuDeviceSetLabel(WGPUDevice device, char const * label);
@@ -1540,7 +1535,7 @@ WGPU_EXPORT void wgpuRenderBundleEncoderSetBindGroup(WGPURenderBundleEncoder ren
 WGPU_EXPORT void wgpuRenderBundleEncoderSetIndexBuffer(WGPURenderBundleEncoder renderBundleEncoder, WGPUBuffer buffer, WGPUIndexFormat format, uint64_t offset, uint64_t size);
 WGPU_EXPORT void wgpuRenderBundleEncoderSetLabel(WGPURenderBundleEncoder renderBundleEncoder, char const * label);
 WGPU_EXPORT void wgpuRenderBundleEncoderSetPipeline(WGPURenderBundleEncoder renderBundleEncoder, WGPURenderPipeline pipeline);
-WGPU_EXPORT void wgpuRenderBundleEncoderSetVertexBuffer(WGPURenderBundleEncoder renderBundleEncoder, uint32_t slot, WGPUBuffer buffer, uint64_t offset, uint64_t size);
+WGPU_EXPORT void wgpuRenderBundleEncoderSetVertexBuffer(WGPURenderBundleEncoder renderBundleEncoder, uint32_t slot, WGPUBuffer buffer /* nullable */, uint64_t offset, uint64_t size);
 
 // Methods of RenderPassEncoder
 WGPU_EXPORT void wgpuRenderPassEncoderBeginOcclusionQuery(WGPURenderPassEncoder renderPassEncoder, uint32_t queryIndex);
@@ -1563,7 +1558,7 @@ WGPU_EXPORT void wgpuRenderPassEncoderSetLabel(WGPURenderPassEncoder renderPassE
 WGPU_EXPORT void wgpuRenderPassEncoderSetPipeline(WGPURenderPassEncoder renderPassEncoder, WGPURenderPipeline pipeline);
 WGPU_EXPORT void wgpuRenderPassEncoderSetScissorRect(WGPURenderPassEncoder renderPassEncoder, uint32_t x, uint32_t y, uint32_t width, uint32_t height);
 WGPU_EXPORT void wgpuRenderPassEncoderSetStencilReference(WGPURenderPassEncoder renderPassEncoder, uint32_t reference);
-WGPU_EXPORT void wgpuRenderPassEncoderSetVertexBuffer(WGPURenderPassEncoder renderPassEncoder, uint32_t slot, WGPUBuffer buffer, uint64_t offset, uint64_t size);
+WGPU_EXPORT void wgpuRenderPassEncoderSetVertexBuffer(WGPURenderPassEncoder renderPassEncoder, uint32_t slot, WGPUBuffer buffer /* nullable */, uint64_t offset, uint64_t size);
 WGPU_EXPORT void wgpuRenderPassEncoderSetViewport(WGPURenderPassEncoder renderPassEncoder, float x, float y, float width, float height, float minDepth, float maxDepth);
 
 // Methods of RenderPipeline