WebNN: Support sign operator for DirectML and tflite backends
This CL defines the sign operation in idl, mojom and implements it for
DirectML and tflite backends.
This CL also adds data type support limits for sign operation and adds
some related WPT validation and conformance tests.
Bug: 40206287, 345271830
Change-Id: I9425c3dfe0e7ac5bf45816cb0bf1ab881e9f0860
Cq-Include-Trybots: luci.chromium.try:win11-blink-rel, mac14.arm64-blink-rel, mac14-blink-rel, mac15.arm64-blink-rel, mac15-blink-rel, linux-blink-rel
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5812182
Reviewed-by: Reilly Grant reillyg@chromium.org
Reviewed-by: Alex Gough ajgo@chromium.org
Commit-Queue: Bin Miao bin.miao@intel.com
Reviewed-by: Weizhong Xia weizhong@google.com
Reviewed-by: Rafael Cintron rafael.cintron@microsoft.com
Cr-Commit-Position: refs/heads/main@{#1349514}