gpu: add ShaderModule.WGSLDescriptor

Signed-off-by: Stephen Gutekanst <stephen@hexops.com>

gpu/TODO-webgpu.h

@@ -1,8 +1,3 @@
-pub const WGPUShaderModuleWGSLDescriptor = extern struct {
-    chain: ChainedStruct,
-    source: [*:0]const u8,
-};
-
 pub const StencilFaceState = extern struct {
     compare: CompareFunction,
     fail_op: StencilOperation,

gpu/src/shader_module.zig

@@ -16,4 +16,9 @@ pub const ShaderModule = enum(usize) {
         code_size: u32,
         code: [*]const u32,
     };
+
+    pub const WGSLDescriptor = extern struct {
+        chain: ChainedStruct,
+        source: [*:0]const u8,
+    };
 };