Enable DepthStencilSamplingTest tests

These tests now pass, since their blocking issue in Tint has been
resolved.

BUG=tint:398

Change-Id: I628bf2be132d2a671ef832951a4798c3c6fef9cb
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/39066
Commit-Queue: Ryan Harrison <rharrison@chromium.org>
Commit-Queue: Austin Eng <enga@chromium.org>
Auto-Submit: Ryan Harrison <rharrison@chromium.org>
Reviewed-by: Austin Eng <enga@chromium.org>

src/tests/end2end/DepthStencilSamplingTests.cpp

@@ -57,9 +57,6 @@ class DepthStencilSamplingTest : public DawnTest {
     void SetUp() override {
         DawnTest::SetUp();
 
-        // TODO(crbug.com/tint/398): GLSL builtins don't work with SPIR-V reader.
-        DAWN_SKIP_TEST_IF(HasToggleEnabled("use_tint_generator"));
-
         wgpu::BufferDescriptor uniformBufferDesc;
         uniformBufferDesc.usage = wgpu::BufferUsage::Uniform | wgpu::BufferUsage::CopyDst;
         uniformBufferDesc.size = sizeof(float);