D3D11 only supports HLSL SM5.0 which doesn't support `space`
(binding group in WGSL). So for D3D11, only one binding group will be
used, and tint will not emit `space` for HLSL, so shaders can be used
with D3D11.
Bug: dawn:1705
Change-Id: Ie0e9868137f10762c5243e188d76f5e41879c2bc
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/125080
Commit-Queue: Peng Huang <penghuang@chromium.org>
Reviewed-by: Ben Clayton <bclayton@google.com>
Kokoro: Ben Clayton <bclayton@google.com>
c00ff7f3c7