GLSL: add .expected.glsl files for all tests.

Bug: tint:1301
Change-Id: Id3a591a2fa0dfdb112046d5c57defbae07483e0d
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/69480
Reviewed-by: Ben Clayton <bclayton@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Stephen White <senorblanco@chromium.org>
diff --git a/test/expressions/binary/add/vec3-scalar/i32.wgsl.expected.glsl b/test/expressions/binary/add/vec3-scalar/i32.wgsl.expected.glsl
new file mode 100644
index 0000000..7882f3b
--- /dev/null
+++ b/test/expressions/binary/add/vec3-scalar/i32.wgsl.expected.glsl
@@ -0,0 +1,14 @@
+#version 310 es
+precision mediump float;
+
+layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
+void f() {
+  ivec3 a = ivec3(1, 2, 3);
+  ivec3 r = (a + 4);
+  return;
+}
+void main() {
+  f();
+}
+
+