Port "Narrow types by satisfies expressions"

[Andarist]

ports microsoft/TypeScript#60782

[Copilot]

Pull Request Overview

Ports the TypeScript change “Narrow types by satisfies expressions” to downstream flow analysis and updates related test baselines.

• Updated several test baselines to reflect new narrowing behavior when a predicate uses satisfies.
• Adjusted declaration and JS baselines for isEmptyString to restore its type‐predicate signature.
• Enhanced flow.go to recognize SatisfiesExpression in type narrowing and reference matching.

Reviewed Changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
testdata/baselines/reference/submodule/compiler/inferTypePredicates.types.diff	Updated expected outputs for .filter(... satisfies boolean) and isEmptyString.
testdata/baselines/reference/submodule/compiler/inferTypePredicates.types	Refined type annotations for filter result and predicate signature.
testdata/baselines/reference/submodule/compiler/inferTypePredicates.js.diff	Cleaned up intermediate boolean signature change for isEmptyString.
testdata/baselines/reference/submodule/compiler/inferTypePredicates.js	Restored isEmptyString as a type predicate (x is "").
testdata/baselines/reference/submodule/compiler/inferTypePredicates.errors.txt.diff	Removed stale error entries related to filter narrowing.
testdata/baselines/reference/submodule/compiler/inferTypePredicates.errors.txt	Updated error count and removed obsolete errors for satisfies.
internal/checker/flow.go	Added ast.KindSatisfiesExpression to narrowType and reference matching.

Comments suppressed due to low confidence (1)

testdata/baselines/reference/submodule/compiler/inferTypePredicates.types:1018

• There aren’t explicit unit tests covering nested satisfies expressions for narrowing; consider adding test cases to validate both direct and nested uses of satisfies in predicates.

->[1, 2, null, 3].filter(  (x) => (x != null) satisfies boolean,) : number[]