[msl] Add newlines between global declarations

This makes it easier to read modules with many struct and function
declarations.

Bug: 42251016
Change-Id: Idd5a2b48db1e7f19384a0061d276bf723756e780
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/194342
Reviewed-by: dan sinclair <dsinclair@chromium.org>
diff --git a/test/tint/builtins/gen/literal/modf/68d8ee.wgsl.expected.ir.msl b/test/tint/builtins/gen/literal/modf/68d8ee.wgsl.expected.ir.msl
index 46573ee..e3c06c7 100644
--- a/test/tint/builtins/gen/literal/modf/68d8ee.wgsl.expected.ir.msl
+++ b/test/tint/builtins/gen/literal/modf/68d8ee.wgsl.expected.ir.msl
@@ -1,12 +1,15 @@
 #include <metal_stdlib>
 using namespace metal;
+
 struct modf_result_vec3_f32 {
   float3 fract;
   float3 whole;
 };
+
 struct VertexOutput {
   float4 pos;
 };
+
 struct vertex_main_outputs {
   float4 VertexOutput_pos [[position]];
 };
@@ -14,18 +17,22 @@
 void modf_68d8ee() {
   modf_result_vec3_f32 res = modf_result_vec3_f32{.fract=float3(-0.5f), .whole=float3(-1.0f)};
 }
+
 fragment void fragment_main() {
   modf_68d8ee();
 }
+
 kernel void compute_main() {
   modf_68d8ee();
 }
+
 VertexOutput vertex_main_inner() {
   VertexOutput out = {};
   out.pos = float4(0.0f);
   modf_68d8ee();
   return out;
 }
+
 vertex vertex_main_outputs vertex_main() {
   return vertex_main_outputs{.VertexOutput_pos=vertex_main_inner().pos};
 }