wgsl: Do not require a semicolon after a struct

Don't generate them either, which generated a lot of test churn.

Fixed: tint:1380
Change-Id: I0a7cfdd2ef0ffe8e7fda111fbc57997b36b949e0
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/77165
Auto-Submit: James Price <jrprice@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
diff --git a/test/samples/compute_boids.wgsl.expected.wgsl b/test/samples/compute_boids.wgsl.expected.wgsl
index 8fd0a19..394631c 100644
--- a/test/samples/compute_boids.wgsl.expected.wgsl
+++ b/test/samples/compute_boids.wgsl.expected.wgsl
@@ -13,7 +13,7 @@
 struct Particle {
   pos : vec2<f32>;
   vel : vec2<f32>;
-};
+}
 
 struct SimParams {
   deltaT : f32;
@@ -23,11 +23,11 @@
   rule1Scale : f32;
   rule2Scale : f32;
   rule3Scale : f32;
-};
+}
 
 struct Particles {
   particles : array<Particle, 5>;
-};
+}
 
 [[binding(0), group(0)]] var<uniform> params : SimParams;