Fix some tests that should have stayed ES5

[jakebailey]

Noticed in #63071.

[Copilot]

Pull request overview

Adjusts a few conformance/compiler tests to run with an ES5 target again (in addition to ES2015) and adds the corresponding ES5 baselines.

Changes:

• Updated three test headers to run with @target: es5,es2015.
• Added ES5 reference baselines for types/symbols/JS (and sourcemap validation where applicable).
• Recorded the new ES5-target diagnostics output in *.errors.txt baselines.

Reviewed changes

Copilot reviewed 16 out of 28 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
tests/cases/conformance/es6/spread/arrayLiteralSpreadES5iterable.ts	Adds ES5 to the test’s target matrix so ES5 downleveling is exercised.
tests/cases/conformance/es6/destructuring/destructuringVariableDeclaration1ES5iterable.ts	Adds ES5 to the test’s target matrix so ES5 downleveling is exercised.
tests/cases/compiler/sourceMapValidationVarInDownLevelGenerator.ts	Adds ES5 to the test’s target matrix to validate downlevel generator sourcemaps.
tests/baselines/reference/sourceMapValidationVarInDownLevelGenerator(target=es5).types	New ES5 baseline for type printing.
tests/baselines/reference/sourceMapValidationVarInDownLevelGenerator(target=es5).symbols	New ES5 baseline for symbol printing.
tests/baselines/reference/sourceMapValidationVarInDownLevelGenerator(target=es5).sourcemap.txt	New ES5 baseline validating sourcemap mappings in downlevel emit.
tests/baselines/reference/sourceMapValidationVarInDownLevelGenerator(target=es5).js	New ES5 baseline for JS emit.
tests/baselines/reference/sourceMapValidationVarInDownLevelGenerator(target=es5).errors.txt	New ES5 baseline capturing diagnostics produced under the ES5 target.
tests/baselines/reference/destructuringVariableDeclaration1ES5iterable(target=es5).types	New ES5 baseline for type printing.
tests/baselines/reference/destructuringVariableDeclaration1ES5iterable(target=es5).symbols	New ES5 baseline for symbol printing.
tests/baselines/reference/destructuringVariableDeclaration1ES5iterable(target=es5).js	New ES5 baseline for JS emit.
tests/baselines/reference/destructuringVariableDeclaration1ES5iterable(target=es5).errors.txt	New ES5 baseline capturing diagnostics produced under the ES5 target.
tests/baselines/reference/arrayLiteralSpreadES5iterable(target=es5).types	New ES5 baseline for type printing.
tests/baselines/reference/arrayLiteralSpreadES5iterable(target=es5).symbols	New ES5 baseline for symbol printing.
tests/baselines/reference/arrayLiteralSpreadES5iterable(target=es5).js	New ES5 baseline for JS emit.
tests/baselines/reference/arrayLiteralSpreadES5iterable(target=es5).errors.txt	New ES5 baseline capturing diagnostics produced under the ES5 target.

[Copilot]

With ES5 included, the test now produces TS5107 ('target=ES5' is deprecated), which then gets baked into the *.errors.txt baseline. This diagnostic text is likely to churn over time and make the test brittle. Consider silencing it via a test header option (e.g. setting the compiler option to ignore this deprecation) so these conformance baselines remain focused on emit/type behavior rather than deprecation messaging.

Suggested change

	// @target: es5,es2015
	// @target: es5,es2015
	// @ignoreDeprecations: 5.0

[Copilot]

Adding ES5 to the target list causes TS5107 deprecation output to appear in the new ES5 *.errors.txt baseline. This tends to be unstable noise for conformance tests. Prefer suppressing the deprecation via a test directive/compiler option so the baseline doesn’t need to pin a deprecation message.

Suggested change

	// @target: es5,es2015
	// @target: es5,es2015
	// @suppressDeprecationWarnings: true

[Copilot]

The ES5 target now triggers TS5107 (ES5 target deprecation), which is captured in the newly added sourceMapValidationVarInDownLevelGenerator(target=es5).errors.txt. Since this test’s intent is sourcemap validation, pinning a deprecation message makes the baseline more fragile than necessary. Consider suppressing the deprecation through a test header/compiler option so the sourcemap baselines stay stable.

Suggested change

	// @target: es5,es2015
	// @target: es5,es2015
	// @ignoreDeprecations: 5.0