Unskip JS emit tests

[jakebailey]

After #1189, we no longer fall over in JS code. Unskip all of these tests so we can start working on them and catch any crashes.

[Copilot]

Pull Request Overview

This PR re-enables a suite of previously skipped JavaScript emit tests following #1189, ensuring that the compiler no longer crashes on valid JS constructs. The key changes include removal of AllowJS test skipping, updates to baseline outputs reflecting modern syntax (e.g. const, arrow functions, object shorthand), and adjustments in emitted declaration files reflecting updated export styles.

• Removed the skip condition for AllowJS in the baseline runner.
• Updated several test baselines to match the expected output from the compiler.
• Modernized code patterns in test baselines (e.g. conversion from var to const, use of arrow functions).

Reviewed Changes

Copilot reviewed 835 out of 835 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
testdata/baselines/reference/submodule/compiler/argumentsReferenceInConstructor2_Js.js	Adds baseline test for a constructor assigning to this["arguments"].
testdata/baselines/reference/submodule/compiler/argumentsReferenceInConstructor1_Js.js.diff	Removes an unnecessary type declaration for the property in the diff output.
testdata/baselines/reference/submodule/compiler/argumentsReferenceInConstructor1_Js.js	Baseline output for a constructor using the property "arguments".
testdata/baselines/reference/submodule/compiler/argumentsPropertyNameInJsMode2.js.diff	Adjusts the declaration signature by removing rest parameters in the baseline diff.
testdata/baselines/reference/submodule/compiler/argumentsPropertyNameInJsMode2.js	Updates the baseline output for function argument emission.
testdata/baselines/reference/submodule/compiler/argumentsPropertyNameInJsMode1.js.diff	Modernizes the code with const and arrow functions, and updates export constructs.
testdata/baselines/reference/submodule/compiler/argumentsPropertyNameInJsMode1.js	Updates baseline output to use concise ES6 syntax and object shorthand.
testdata/baselines/reference/submodule/compiler/amdLikeInputDeclarationEmit.js.diff	Changes module export from export = ExtendedClass to an empty export; reflecting updated AMD handling.
testdata/baselines/reference/submodule/compiler/amdLikeInputDeclarationEmit.js	Updates baseline for module export declaration and corresponding export handling.
testdata/baselines/reference/submodule/compiler/ambientRequireFunction(module=preserve).js.diff	Replaces var with const for modern require usage in preserved module mode.
testdata/baselines/reference/submodule/compiler/ambientRequireFunction(module=preserve).js	Reflects the updated const usage for require in the baseline output.
testdata/baselines/reference/submodule/compiler/ambientRequireFunction(module=commonjs).js.diff	Modernizes require usage (var → const) for commonjs module output.
testdata/baselines/reference/submodule/compiler/ambientRequireFunction(module=commonjs).js	Updates baseline output for commonjs modules with modern syntax.
testdata/baselines/reference/submodule/compiler/allowJscheckJsTypeParameterNoCrash.js.diff	Modernizes code by replacing var with const and switching to shorthand method definitions.
testdata/baselines/reference/submodule/compiler/allowJscheckJsTypeParameterNoCrash.js	Updates baseline output for improved JS type handling with modern syntax.
testdata/baselines/reference/submodule/compiler/accessorDeclarationEmitJs.js.diff	Replaces namespace exports with explicit constant object declarations in the d.ts output.
testdata/baselines/reference/submodule/compiler/accessorDeclarationEmitJs.js	Updates JS and d.ts baseline outputs for accessor declarations using modern export style.
testdata/baselines/reference/conformance/typeTagForMultipleVariableDeclarations.js	Updates baseline output for type tag declarations in JS with multiple variables.
testdata/baselines/reference/conformance/deepElementAccessExpressionInJS.js	Provides updated baseline output for deep element access expressions in JS.
internal/testutil/tsbaseline/js_emit_baseline.go	Removes the AllowJS skip check to enable these tests, reflecting the updated compiler behavior.

[weswigham]

For sure a lot of these diffs need to be looked at, but if we want some baselines to start with, this can be it.

[jakebailey]

Yeah, I want to look at this a little harder before, because it's failing race checks due to emit ordering problems, which is I think must be fixed before we are able to merge it.

[jakebailey]

Okay, I triaged the two failures (and cleaned up skipped tests a little bit). Theoretically this should pass CI.