Fix generation of f16 values.

The generator script was not using the test values for `f16`, they
always got a zero initialization. This CL fixes the script to generate
`f16` values.

Change-Id: I95e8f2c7007251a646de05b4f7fe0aad14e740f8
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/109342
Reviewed-by: Ben Clayton <bclayton@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Dan Sinclair <dsinclair@chromium.org>
diff --git a/test/tint/builtins/gen/literal/determinant/fc12a5.wgsl b/test/tint/builtins/gen/literal/determinant/fc12a5.wgsl
index 2b22f37..2741b6d 100644
--- a/test/tint/builtins/gen/literal/determinant/fc12a5.wgsl
+++ b/test/tint/builtins/gen/literal/determinant/fc12a5.wgsl
@@ -25,7 +25,7 @@
 
 // fn determinant(mat<2, 2, f16>) -> f16
 fn determinant_fc12a5() {
-  var res: f16 = determinant(mat2x2<f16>(f16(), f16(), f16(), f16()));
+  var res: f16 = determinant(mat2x2<f16>(1.h, 1.h, 1.h, 1.h));
 }
 
 @vertex