Support math trunc

[titaiwangms]

Fix pytorch/pytorch#166110

[codecov]

Codecov Report

❌ Patch coverage is 66.66667% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 70.42%. Comparing base (8a94ad6) to head (6a084dd).
⚠️ Report is 3 commits behind head on main.

Files with missing lines	Patch %	Lines
onnxscript/function_libs/torch_lib/ops/core.py	66.66%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2653      +/-   ##
==========================================
- Coverage   70.46%   70.42%   -0.05%     
==========================================
  Files         224      224              
  Lines       26572    26593      +21     
  Branches     2637     2641       +4     
==========================================
+ Hits        18723    18727       +4     
- Misses       6928     6943      +15     
- Partials      921      923       +2     

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