[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/textureLoad/143d84.wgsl.expected.ir.msl b/test/tint/builtins/gen/literal/textureLoad/143d84.wgsl.expected.ir.msl
index a579538..8a537c4 100644
--- a/test/tint/builtins/gen/literal/textureLoad/143d84.wgsl.expected.ir.msl
+++ b/test/tint/builtins/gen/literal/textureLoad/143d84.wgsl.expected.ir.msl
@@ -1,13 +1,16 @@
 #include <metal_stdlib>
 using namespace metal;
+
 struct tint_module_vars_struct {
   texture2d_array<float, access::read> arg_0;
   device float4* prevent_dce;
 };
+
 struct VertexOutput {
   float4 pos;
   float4 prevent_dce;
 };
+
 struct vertex_main_outputs {
   float4 VertexOutput_pos [[position]];
   float4 VertexOutput_prevent_dce [[user(locn0)]] [[flat]];
@@ -17,20 +20,24 @@
   float4 res = tint_module_vars.arg_0.read(uint2(int2(1)), 1u);
   return res;
 }
+
 fragment void fragment_main(texture2d_array<float, access::read> arg_0 [[texture(0)]], device float4* prevent_dce [[buffer(0)]]) {
   tint_module_vars_struct const tint_module_vars = tint_module_vars_struct{.arg_0=arg_0, .prevent_dce=prevent_dce};
   (*tint_module_vars.prevent_dce) = textureLoad_143d84(tint_module_vars);
 }
+
 kernel void compute_main(texture2d_array<float, access::read> arg_0 [[texture(0)]], device float4* prevent_dce [[buffer(0)]]) {
   tint_module_vars_struct const tint_module_vars = tint_module_vars_struct{.arg_0=arg_0, .prevent_dce=prevent_dce};
   (*tint_module_vars.prevent_dce) = textureLoad_143d84(tint_module_vars);
 }
+
 VertexOutput vertex_main_inner(tint_module_vars_struct tint_module_vars) {
   VertexOutput out = {};
   out.pos = float4(0.0f);
   out.prevent_dce = textureLoad_143d84(tint_module_vars);
   return out;
 }
+
 vertex vertex_main_outputs vertex_main(texture2d_array<float, access::read> arg_0 [[texture(0)]]) {
   tint_module_vars_struct const tint_module_vars = tint_module_vars_struct{.arg_0=arg_0};
   VertexOutput const v = vertex_main_inner(tint_module_vars);