Add WGSL parsing tests

tests/convert.rs

@@ -0,0 +1,15 @@
+fn convert_wgsl(name: &str) {
+    let path = format!("{}/test-data/{}.wgsl", env!("CARGO_MANIFEST_DIR"), name);
+    let input = std::fs::read_to_string(path).unwrap();
+    let _module = naga::front::wgsl::parse_str(&input).unwrap();
+}
+
+#[test]
+fn convert_quad() {
+    convert_wgsl("quad");
+}
+
+#[test]
+fn convert_boids() {
+    convert_wgsl("boids");
+}