GLSL: put std430 packing on all buffer variables.

This is not 100% correct (the exceptions for mat2 and friends are not
implemented yet), but gets more tests passing in Dawn.

Bug: tint:1415
Change-Id: Ia11c63a5236f35e724431a65ddb6ef3c598775d0
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/79380
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: David Neto <dneto@google.com>
Commit-Queue: Stephen White <senorblanco@chromium.org>
diff --git a/test/builtins/gen/isNormal/b00ab1.wgsl.expected.glsl b/test/builtins/gen/isNormal/b00ab1.wgsl.expected.glsl
index ed74f8e..0084bec 100644
--- a/test/builtins/gen/isNormal/b00ab1.wgsl.expected.glsl
+++ b/test/builtins/gen/isNormal/b00ab1.wgsl.expected.glsl
@@ -31,8 +31,8 @@
   return;
 }
 Error parsing GLSL shader:
-ERROR: 0:5: 'uint2' : undeclared identifier
-ERROR: 0:5: '' : compilation terminated
+ERROR: 0:5: 'uint2' : undeclared identifier 
+ERROR: 0:5: '' : compilation terminated 
 ERROR: 2 compilation errors.  No code generated.
 
 
@@ -60,8 +60,8 @@
   return;
 }
 Error parsing GLSL shader:
-ERROR: 0:5: 'uint2' : undeclared identifier
-ERROR: 0:5: '' : compilation terminated
+ERROR: 0:5: 'uint2' : undeclared identifier 
+ERROR: 0:5: '' : compilation terminated 
 ERROR: 2 compilation errors.  No code generated.
 
 
@@ -90,8 +90,8 @@
   return;
 }
 Error parsing GLSL shader:
-ERROR: 0:5: 'uint2' : undeclared identifier
-ERROR: 0:5: '' : compilation terminated
+ERROR: 0:5: 'uint2' : undeclared identifier 
+ERROR: 0:5: '' : compilation terminated 
 ERROR: 2 compilation errors.  No code generated.