tint: Fix doxygen failure

Bug: tint:1495
Change-Id: I4e9d0d58e0f49c80ea7709d5baecf0eca80e297a
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/86529
Auto-Submit: Ben Clayton <bclayton@google.com>
Reviewed-by: Antonio Maiorano <amaiorano@google.com>
Commit-Queue: Antonio Maiorano <amaiorano@google.com>

src/tint/writer/glsl/test_helper.h

@@ -59,6 +59,7 @@ class TestHelperBase : public BODY, public ProgramBuilder {
   /// @note The generator is only built once. Multiple calls to Build() will
   /// return the same GeneratorImpl without rebuilding.
   /// @param version the GLSL version
+  /// @param options the GLSL backend options
   /// @return the built generator
   GeneratorImpl& SanitizeAndBuild(Version version = Version(),
                                   const Options& options = {}) {