Fix invert astral capture regression

[JLHwung]

Fix Babel test262 errors from recent regressions

not ok 11237 test/language/literals/regexp/u-astral-char-class-invert.js default # (expected success, got runtime error)
  ---
  name: Test262Error
  message: 'Expected SameValue(«�», «null») to be true'
  stack: >
    Test262Error: Expected SameValue(«�», «null») to be true

    /home/runner/work/babel/babel/babel-test262-runner/lib/run-tests/index.js:80:17

  ...
not ok 11239 test/language/literals/regexp/u-astral-char-class-invert.js strict mode # (expected success, got runtime error)
  ---
  name: Test262Error
  message: 'Expected SameValue(«�», «null») to be true'
  stack: >
    Test262Error: Expected SameValue(«�», «null») to be true

    /home/runner/work/babel/babel/babel-test262-runner/lib/run-tests/index.js:80:17

Other test262 errors will be tracked in jviereck/regjsparser#134

[JLHwung]

Adding ^ and $ does affect the capturing behaviour, which is why the bug is not caught in previous tests. Here we construct test regex directly from the transpiled regex.