Assume alwaysStrict

[jakebailey]

This follows from microsoft/TypeScript#63089

alwaysStrict is assumed to be true everywhere.

This gets rid of the last SourceFileAffectingCompilerOptions field, so that no longer exists.

The only compiler options that matter for the AST are now those used for ExternalModuleIndicatorOptions.

[Copilot]

Pull request overview

Assumes alwaysStrict is effectively always enabled across the compiler/transform pipeline, removing SourceFileAffectingCompilerOptions and updating parsing/binding behavior and test baselines to match.

Changes:

• Remove SourceFileAffectingCompilerOptions and associated plumbing from parse/bind/emit paths.
• Treat strict mode as always-on for emitted output and for binding non-declaration files.
• Update/trim baselines and skip tests that explicitly set alwaysStrict=false.

Reviewed changes

Copilot reviewed 300 out of 373 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
internal/transformers/estransforms/usestrict.go	Always inject "use strict" during transform.
internal/ast/parseoptions.go	Remove SourceFileAffectingCompilerOptions from parse options and delete helper.
internal/binder/binder.go	Bind in strict mode without consulting source-file affecting options.
internal/binder/binder_test.go	Update benchmark to reflect removed parse option field.
internal/compiler/fileloader.go	Stop computing/passing source-file affecting options; keep external module indicator options.
internal/compiler/program.go	Validate that alwaysStrict=false is unsupported and produce a diagnostic.
internal/core/compileroptions.go	Remove cached source-file affecting options; keep alwaysStrict only for parsing/validation.
internal/project/autoimport.go	Remove passing source-file affecting options while parsing for auto-import registry.
internal/project/session_test.go	Adjust tsconfig used in session test.
internal/testutil/tsbaseline/js_emit_baseline.go	Remove passing source-file affecting options when parsing in JS emit baselines.
internal/testutil/harnessutil/harnessutil.go	Skip tests that explicitly request alwaysStrict=false.
testdata/baselines/reference/**	Remove/update reference baselines affected by always-strict behavior and skipped tests.