tint: Suffix builtin return types with '_f32'

If the template type is f32.

See: https://github.com/gpuweb/gpuweb/pull/3629
Change-Id: Ia686d77b4dbc169d7ef69a91d67e45357bee199f
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/111442
Reviewed-by: David Neto <dneto@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>
diff --git a/test/tint/builtins/modf/vector/runtime.wgsl.expected.glsl b/test/tint/builtins/modf/vector/runtime.wgsl.expected.glsl
index fd2df75..0090769 100644
--- a/test/tint/builtins/modf/vector/runtime.wgsl.expected.glsl
+++ b/test/tint/builtins/modf/vector/runtime.wgsl.expected.glsl
@@ -1,12 +1,12 @@
 #version 310 es
 
-struct modf_result_vec2 {
+struct modf_result_vec2_f32 {
   vec2 fract;
   vec2 whole;
 };
 
-modf_result_vec2 tint_modf(vec2 param_0) {
-  modf_result_vec2 result;
+modf_result_vec2_f32 tint_modf(vec2 param_0) {
+  modf_result_vec2_f32 result;
   result.fract = modf(param_0, result.whole);
   return result;
 }
@@ -14,7 +14,7 @@
 
 void tint_symbol() {
   vec2 tint_symbol_1 = vec2(1.25f, 3.75f);
-  modf_result_vec2 res = tint_modf(tint_symbol_1);
+  modf_result_vec2_f32 res = tint_modf(tint_symbol_1);
   vec2 tint_symbol_2 = res.fract;
   vec2 whole = res.whole;
 }