tint/writer/wgsl: Emit 'f' suffix on FloatLiteralExpressions

If the literal was constructed with an 'f', make sure we print it.

Bug: tint:1504
Change-Id: I6f04e31a166919c07574db56b0a2063ce5b8ca5c
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/91965
Reviewed-by: Antonio Maiorano <amaiorano@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>
diff --git a/test/tint/array/strides.spvasm.expected.wgsl b/test/tint/array/strides.spvasm.expected.wgsl
index 6713a16..14e0a9e 100644
--- a/test/tint/array/strides.spvasm.expected.wgsl
+++ b/test/tint/array/strides.spvasm.expected.wgsl
@@ -26,7 +26,7 @@
   let x_28 : Arr = s.a[3i].el[2i];
   let x_32 : f32 = s.a[3i].el[2i][1i].el;
   s.a = array<strided_arr_1, 4u>();
-  s.a[3i].el[2i][1i].el = 5.0;
+  s.a[3i].el[2i][1i].el = 5.0f;
   return;
 }