GLSL: move entry point handling to CanonicalizeEntryPointIO transform.

Move builtin_to_string() and builtin_type() to
the CanonicalizeEntryPointIO transform. Use the former to
rename entry point IO variables to the gl_ names, and the latter
to cast values to the correct type.

Change-Id: Iddfad574ddd660ff1bfd89a399a001b967b6b67e
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/78380
Reviewed-by: James Price <jrprice@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Stephen White <senorblanco@chromium.org>

test/ptr_ref/load/local/i32.spvasm.expected.glsl

@@ -8,13 +8,12 @@ void main_1() {
   return;
 }
 
-layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
 void tint_symbol() {
   main_1();
-  return;
 }
 
+layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
 void main() {
   tint_symbol();
+  return;
 }
-

test/ptr_ref/load/local/i32.wgsl.expected.glsl

@@ -1,14 +1,13 @@
 #version 310 es
 precision mediump float;
 
-layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
 void tint_symbol() {
   int i = 123;
   int use = (i + 1);
-  return;
 }
 
+layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
 void main() {
   tint_symbol();
+  return;
 }
-

test/ptr_ref/load/local/ptr_function.wgsl.expected.glsl

@@ -1,14 +1,13 @@
 #version 310 es
 precision mediump float;
 
-layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
 void tint_symbol() {
   int i = 123;
   int use = (i + 1);
-  return;
 }
 
+layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
 void main() {
   tint_symbol();
+  return;
 }
-

test/ptr_ref/load/local/ptr_private.wgsl.expected.glsl

@@ -2,13 +2,12 @@
 precision mediump float;
 
 int i = 123;
-layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
 void tint_symbol() {
   int use = (i + 1);
-  return;
 }
 
+layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
 void main() {
   tint_symbol();
+  return;
 }
-

test/ptr_ref/load/local/ptr_storage.wgsl.expected.glsl

@@ -8,13 +8,12 @@ struct S {
 layout(binding = 0) buffer S_1 {
   int a;
 } v;
-layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
 void tint_symbol() {
   int use = (v.a + 1);
-  return;
 }
 
+layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
 void main() {
   tint_symbol();
+  return;
 }
-

test/ptr_ref/load/local/ptr_uniform.wgsl.expected.glsl

@@ -9,13 +9,12 @@ layout(binding = 0) uniform S_1 {
   int a;
 } v;
 
-layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
 void tint_symbol() {
   int use = (v.a + 1);
-  return;
 }
 
+layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
 void main() {
   tint_symbol();
+  return;
 }
-

test/ptr_ref/load/local/ptr_workgroup.wgsl.expected.glsl

@@ -2,11 +2,7 @@
 precision mediump float;
 
 shared int i;
-struct tint_symbol_2 {
-  uint local_invocation_index;
-};
-
-void tint_symbol_inner(uint local_invocation_index) {
+void tint_symbol(uint local_invocation_index) {
   {
     i = 0;
   }
@@ -16,15 +12,7 @@ void tint_symbol_inner(uint local_invocation_index) {
 }
 
 layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
-void tint_symbol(tint_symbol_2 tint_symbol_1) {
-  tint_symbol_inner(tint_symbol_1.local_invocation_index);
+void main() {
+  tint_symbol(gl_LocalInvocationIndex);
   return;
 }
-
-
-void main() {
-  tint_symbol_2 inputs;
-  inputs.local_invocation_index = uint(gl_LocalInvocationIndex);
-  tint_symbol(inputs);
-}
-

test/ptr_ref/load/local/struct_field.spvasm.expected.glsl

@@ -13,13 +13,12 @@ void main_1() {
   return;
 }
 
-layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
 void tint_symbol() {
   main_1();
-  return;
 }
 
+layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
 void main() {
   tint_symbol();
+  return;
 }
-

test/ptr_ref/load/local/struct_field.wgsl.expected.glsl

@@ -5,14 +5,14 @@ struct S {
   int i;
 };
 
-layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
 void tint_symbol() {
   S V = S(0);
   int i = V.i;
   return;
 }
 
+layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
 void main() {
   tint_symbol();
+  return;
 }
-