[Ascend] fuj / fix-index-error-for-ascend

[jingguo-st]

Motivation and Context

some bugs found in index implementation: use split to get the nonzero elements for bool type indices

Checklist

Before PR:

• I have read and followed the workflow indicated in the Contributors.md to create this PR.
• Pre-commit or linting tools indicated in Contributors.md are used to fix the potential lint issues.
• Bug fixes are covered by unit tests, the case that causes the bug should be added in the unit tests.
• New functionalities are covered by complete unit tests. If not, please add more unit test to ensure the correctness.
• The documentation has been modified accordingly, including docstring or example tutorials.

After PR:

• CLA has been signed and all committers have signed the CLA in this PR.