Update README.md

[metascroy]

Add -DSUPPORT_REGEX_LOOKAHEAD to readme.

[pytorch-bot]

🔗 Helpful Links

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❌ 3 New Failures, 3 Pending

As of commit d11c3b9 with merge base 385d860 ():

NEW FAILURES - The following jobs have failed:

• Check Labels / Check labels (gh)
  RuntimeError: Error checking labels: PR does not have required labels
• pull / android / run-emulator (gh)
  The process '/usr/bin/sh' failed with exit code 255
• pull / unittest-editable / macos / macos-job (gh)
  RuntimeError: Command bash /Users/ec2-user/runner/_work/_temp/exec_script failed with exit code 1

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