add static property duplicate name check

[iisaduan]

fixes #3484

[Copilot]

Pull request overview

Fixes #3484 by restoring TS2699 diagnostics for static class members that conflict with built-in Function properties when useDefineForClassFields is false, aligning tsgo’s output with expected baselines and removing an obsolete triaged diff.

Changes:

• Add a checker pass during class-like declaration checking to report TS2699 for conflicting static member names (e.g. name, length, caller, arguments, prototype) under the relevant compiler option conditions.
• Update the conformance error baseline for staticPropertyNameConflicts(...,usedefineforclassfields=false) to include the restored TS2699 errors.
• Remove the now-unneeded triaged .diff baseline for the same conformance case.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

File	Description
internal/checker/checker.go	Adds a class-like static member conflict check intended to restore TS2699 for built-in Function property name collisions.
testdata/baselines/reference/submodule/conformance/staticPropertyNameConflicts(target=es2015,usedefineforclassfields=false).errors.txt	Updates expected errors to reflect restored TS2699 diagnostics (now matching upstream expectations for this configuration).
testdata/baselines/reference/submoduleTriaged/conformance/staticPropertyNameConflicts(target=es2015,usedefineforclassfields=false).errors.txt.diff	Removes an obsolete triaged diff baseline because the behavior is no longer divergent.