Cherry-pick "Refactor Regexp.prototype" am: c00e914da2 am: 78139c51eb am: 20093377c7

Original change: https://googleplex-android-review.googlesource.com/c/platform/external/chromium-libpac/+/12135061

Change-Id: Ic6742b4146aadd5bc1a5b6b9de0591a13a038386
tree: 376f1116cea2d05d2c5384fe8feedb6b876518b6
  1. src/
  2. test/
  3. Android.mk
  4. LICENSE
  5. MODULE_LICENSE_BSD
  6. NOTICE
  7. README