Issue "'{0}' declarations can only be declared inside a block." for block-scoped variables in presence of parse errors

[Andarist]

fixes#61734

[Copilot]

Pull Request Overview

This PR fixes inconsistent handling of block-scoped declarations in the presence of parse errors by switching from grammarErrorOnNode to directly adding diagnostics, and adds tests to verify the TS1156 error for const, let, using, and await using declarations outside blocks.

• Replace grammarErrorOnNode calls with diagnostics.add(createDiagnosticForNode(...)) in the checker.
• Introduce a new compiler-test file covering parse-error scenarios for block-scoped declarations.
• Update baselines for types, symbols, and error outputs to reflect the new diagnostic behavior.

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
tests/cases/compiler/disallowedBlockScopedInPresenceOfParseErrors1.ts	New test cases for invalid block-scoped declarations with parse errors
tests/baselines/reference/disallowedBlockScopedInPresenceOfParseErrors1.types	Updated baseline types output
tests/baselines/reference/disallowedBlockScopedInPresenceOfParseErrors1.symbols	Updated baseline symbol output
tests/baselines/reference/disallowedBlockScopedInPresenceOfParseErrors1.errors.txt	Updated baseline error messages
src/compiler/checker.ts	Swapped grammarErrorOnNode return into a direct diagnostics.add call

Comments suppressed due to low confidence (1)

src/compiler/checker.ts:52839

• The original code returned immediately after calling grammarErrorOnNode, short-circuiting further checks. Removing the return changes control flow and may allow unintended processing after the diagnostic. Consider restoring the return to maintain the original behavior.

diagnostics.add(createDiagnosticForNode(node, Diagnostics._0_declarations_can_only_be_declared_inside_a_block, keyword));