Update release 6.0 with main

[milseman]

No description provided.

[milseman]

• Explanation: Some improvements to main didn't get cherry-picked to 6.0 release. These include improvements to refactoring support, important performance improvements, and fixes to tests.
• Original PRs:
  • Overhaul quantification optimizations #710 Overhaul quantification optimizations
  • Support change matching options in Regex refactoring #738 Support change matching options in Regex refactoring
  • Work around compiler type checker issue #737 Work around compiler type checker issue
• Risk: Low. Already on main.
• Reviewed by: @natecook1000
• Resolves: rdar://129068468
• Tests: Full swift-ci testing and full string-processing package testing

[milseman]

@swift-ci please test

[natecook1000]

[milseman]

@swift-ci please test windows platform

[milseman]

rdar://129068468