OpenGL: Support B2T and T2T copies with BC formats

This patch implements the creation, buffer-to-texture copies and
texture-to-texture copies with BC formats on OpenGL backend. Note that
OpenGL SPEC also has the same issue about texture-to-texture copies
with compressed textures as Vulkan SPEC, so we have to skip the related
case.

The texture-to-buffer copies with BC formats and related end2end tests
will be supported in the following patches.

BUG=dawn:42
TEST=dawn_end2end_tests

Change-Id: I76b16862259cb2df77f202ed7ed433d41aa3cd47
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/10220
Commit-Queue: Jiawei Shao <jiawei.shao@intel.com>
Reviewed-by: Austin Eng <enga@chromium.org>

src/dawn_native/opengl/TextureGL.cpp

@@ -187,6 +187,11 @@ namespace dawn_native { namespace opengl {
                                GLint baseArrayLayer,
                                uint32_t layerCount) {
         const OpenGLFunctions& gl = ToBackend(GetDevice())->gl;
+        // TODO(jiawei.shao@intel.com): initialize the textures with compressed formats.
+        if (GetFormat().isCompressed) {
+            return;
+        }
+
         if (GetFormat().HasDepthOrStencil()) {
             bool doDepthClear = GetFormat().HasDepth();
             bool doStencilClear = GetFormat().HasStencil();