GLSL: clean up GLSL output whitespace generation.

More line() and less std::endl.
More automated indents and less manual spacing.
Put a single newline after every struct and function declaration.

Note that this does touch every test result, but only affects whitespace.

Change-Id: I7506b9029b79b91fb335911dba44369b36f09bbe
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/78300
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
Commit-Queue: Stephen White <senorblanco@chromium.org>
diff --git a/test/shadowing/alias/param.wgsl.expected.glsl b/test/shadowing/alias/param.wgsl.expected.glsl
index cd776caf..b685a99 100644
--- a/test/shadowing/alias/param.wgsl.expected.glsl
+++ b/test/shadowing/alias/param.wgsl.expected.glsl
@@ -5,12 +5,12 @@
 void unused_entry_point() {
   return;
 }
+
 void main() {
   unused_entry_point();
 }
 
-
-
 void f(int a_1) {
   int b = a_1;
 }
+