Update src/tint unittests to new @stage format.

This CL updates all of the Tint unittests to the new @stage shorter
syntax. This also updates the WGSL writer to emit the new short forms
instead of using the deprecated form.

Bug: tint:1503
Change-Id: I8c49e5319a19cccb5b4b5078f3ab39c50f31a9a8
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/92483
Reviewed-by: Ben Clayton <bclayton@google.com>
Commit-Queue: Dan Sinclair <dsinclair@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>

test/tint/expressions/binary/bit-and/scalar-scalar/bool.wgsl

@@ -1,4 +1,4 @@
-@stage(compute) @workgroup_size(1)
+@compute @workgroup_size(1)
 fn f() {
     let a = true;
     let b = false;

test/tint/expressions/binary/bit-and/scalar-scalar/bool.wgsl.expected.wgsl

@@ -1,4 +1,4 @@
-@stage(compute) @workgroup_size(1)
+@compute @workgroup_size(1)
 fn f() {
   let a = true;
   let b = false;

test/tint/expressions/binary/bit-and/scalar-scalar/i32.wgsl

@@ -1,4 +1,4 @@
-@stage(compute) @workgroup_size(1)
+@compute @workgroup_size(1)
 fn f() {
     let a = 1;
     let b = 2;

test/tint/expressions/binary/bit-and/scalar-scalar/i32.wgsl.expected.wgsl

@@ -1,4 +1,4 @@
-@stage(compute) @workgroup_size(1)
+@compute @workgroup_size(1)
 fn f() {
   let a = 1;
   let b = 2;

test/tint/expressions/binary/bit-and/scalar-scalar/u32.wgsl

@@ -1,4 +1,4 @@
-@stage(compute) @workgroup_size(1)
+@compute @workgroup_size(1)
 fn f() {
     let a = 1u;
     let b = 2u;

test/tint/expressions/binary/bit-and/scalar-scalar/u32.wgsl.expected.wgsl

@@ -1,4 +1,4 @@
-@stage(compute) @workgroup_size(1)
+@compute @workgroup_size(1)
 fn f() {
   let a = 1u;
   let b = 2u;

test/tint/expressions/binary/bit-and/vec3-vec3/bool.wgsl

@@ -1,4 +1,4 @@
-@stage(compute) @workgroup_size(1)
+@compute @workgroup_size(1)
 fn f() {
     let a = vec3<bool>(true, true, false);
     let b = vec3<bool>(true, false, true);

test/tint/expressions/binary/bit-and/vec3-vec3/bool.wgsl.expected.wgsl

@@ -1,4 +1,4 @@
-@stage(compute) @workgroup_size(1)
+@compute @workgroup_size(1)
 fn f() {
   let a = vec3<bool>(true, true, false);
   let b = vec3<bool>(true, false, true);

test/tint/expressions/binary/bit-and/vec3-vec3/i32.wgsl

@@ -1,4 +1,4 @@
-@stage(compute) @workgroup_size(1)
+@compute @workgroup_size(1)
 fn f() {
     let a = vec3<i32>(1, 2, 3);
     let b = vec3<i32>(4, 5, 6);

test/tint/expressions/binary/bit-and/vec3-vec3/i32.wgsl.expected.wgsl

@@ -1,4 +1,4 @@
-@stage(compute) @workgroup_size(1)
+@compute @workgroup_size(1)
 fn f() {
   let a = vec3<i32>(1, 2, 3);
   let b = vec3<i32>(4, 5, 6);

test/tint/expressions/binary/bit-and/vec3-vec3/u32.wgsl

@@ -1,4 +1,4 @@
-@stage(compute) @workgroup_size(1)
+@compute @workgroup_size(1)
 fn f() {
     let a = vec3<u32>(1u, 2u, 3u);
     let b = vec3<u32>(4u, 5u, 6u);

test/tint/expressions/binary/bit-and/vec3-vec3/u32.wgsl.expected.wgsl

@@ -1,4 +1,4 @@
-@stage(compute) @workgroup_size(1)
+@compute @workgroup_size(1)
 fn f() {
   let a = vec3<u32>(1u, 2u, 3u);
   let b = vec3<u32>(4u, 5u, 6u);