Patterns parsing: fix record-typed variable patterns before certain tokens.

Previously, if a record-typed variable pattern lacked a `var` or
`final` keyword, and was followed by one of the tokens `||`, `&&`,
`as`, `?`, `!`, `when`, or `=>`, the parser would fail to recognize
it. This happened because the call to `computeVariablePatternType`
wasn't passing `true` for the optional parameter `required`; that in
turn placed `computeType` in a mode where it believed it was parsing a
potentially ambiguous construct in a top-level declaration, and hence
it would only accept the record type if the variable name was followed
by something that looked like part of a correct declaration (e.g. a
comma).

The fix is to pass `true` for the optional parameter `required` of
`computeVariablePatternType`. This places `computeType` in a mode
where it accepts the record type regardless of what follows it. This
is correct behavior since at the point where a variable pattern is
being parsed, ambiguities have already been taken care of and the
construct being parsed is most definitely a variable pattern.

Fixes #52521.

Change-Id: If20772ad914827a29df45c27eefb382ec1f470d2
Bug: https://github.com/dart-lang/sdk/issues/52521
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/305848
Reviewed-by: Jens Johansen <jensj@google.com>
Commit-Queue: Paul Berry <paulberry@google.com>
242 files changed
tree: e57e406bd39a002bf108b7d1e1d85324f0fd42c2
  1. .dart_tool/
  2. .github/
  3. benchmarks/
  4. build/
  5. docs/
  6. pkg/
  7. runtime/
  8. samples/
  9. sdk/
  10. tests/
  11. third_party/
  12. tools/
  13. utils/
  14. .clang-format
  15. .gitattributes
  16. .gitconfig
  17. .gitignore
  18. .gn
  19. .mailmap
  20. .style.yapf
  21. .vpython
  22. AUTHORS
  23. BUILD.gn
  24. CHANGELOG.md
  25. codereview.settings
  26. CONTRIBUTING.md
  27. DEPS
  28. LICENSE
  29. OWNERS
  30. PATENT_GRANT
  31. PRESUBMIT.py
  32. README.dart-sdk
  33. README.md
  34. sdk.code-workspace
  35. sdk_args.gni
  36. SECURITY.md
  37. WATCHLISTS
README.md

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