Obtain late-bound symbol in error reporting

[ahejlsberg]

Fixes #4224.

[Copilot]

Pull request overview

This PR fixes diagnostic reporting for late-bound (computed-name) class members so incompatibilities are reported as member-level errors (e.g. TS2416) rather than as a class-level “incorrectly extends/implements” error (e.g. TS2415/TS2420), aligning tsgo output with upstream TypeScript behavior.

Changes:

• Update issueMemberSpecificError to use the late-bound symbol for computed-name members when selecting a property to report against.
• Add a new compiler regression test (sameComputedNameError.ts) with corresponding .errors/.types/.symbols baselines.
• Update submodule conformance baselines and remove an now-unneeded accepted diff entry for symbolProperty24.

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
internal/checker/checker.go	Adjust member-specific error reporting to use late-bound symbols for computed members.
testdata/tests/cases/compiler/sameComputedNameError.ts	New regression test for computed-name override error reporting.
testdata/baselines/reference/compiler/sameComputedNameError.errors.txt	Baseline asserting TS2416 on the computed-name member in the derived class.
testdata/baselines/reference/compiler/sameComputedNameError.types	Type baseline for the new regression test.
testdata/baselines/reference/compiler/sameComputedNameError.symbols	Symbol baseline for the new regression test.
testdata/baselines/reference/submodule/conformance/symbolProperty24.errors.txt	Updated upstream conformance baseline now expecting member-level TS2416 reporting.
testdata/submoduleAccepted.txt	Remove symbolProperty24 from accepted diffs now that the port matches upstream.
testdata/baselines/reference/submoduleAccepted/conformance/symbolProperty24.errors.txt.diff	Delete obsolete accepted diff file (no longer needed after baseline alignment).

[ahejlsberg]

Yeah, we should preserve the nil check