[TS] Support PtrCall

[Lipen]

This PR adds the support for PtrCallExpr.

Currently, only local (non-input) lambda calls are supported. In IR, such calls are represented via PtrCallExpr(ptr), where ptr is a local with %AM prefix. Local's name corresponds to the anonymous method name, which is auto-generated for each lambda in the source code. We try to resolve this method uniquely, other cases are not yet supported.

Note that if the lambda is actually a closure, it should receive all captured variables as arguments (more importantly, those args go before normal args!). Since the corresponding LexicalEnvType is not yet supported, we also do not have a proper support for closures, yet.

Since more complex cases with PtrCall are inter-connected with closures, this PR also includes some support for closures. Lately, we introduced the support for LexicalEnvType and ClosureFieldRef in the model, and now USVM can handle captured locals for closures. Currently, on the call-site, we allocate a "closure object", fill its "fields" with captured locals, and save it in TsState. In the caller, when resolving ClosureFieldRef (which is actually a simplified InstanceFieldRef), we just read the necessary fields from the saved object.

[Copilot]

Pull Request Overview

This PR introduces basic support for pointer-based lambda calls (PtrCallExpr) in the TypeScript interpreter and state, along with tests for local lambdas. Key changes include:

• Adding a new test case and sample (callLocalLambda) to validate pointer call support for non-capturing lambdas.
• Extending TsState, TsMethodResult, TsInterpreter, and TsExprResolver to track method references and resolve/call lambdas via pointers.
• Consolidating mock call logic into a new mockMethodCall helper in org.usvm.api.TsMock.

Reviewed Changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
usvm-ts/src/test/resources/samples/Call.ts	Add callLocalLambda sample method
usvm-ts/src/test/kotlin/org/usvm/samples/Call.kt	Add test call local lambda JUnit test
usvm-ts/src/main/kotlin/org/usvm/machine/state/TsStateUtils.kt	Fix lastStmt getter and swap args for RegularCall
usvm-ts/src/main/kotlin/org/usvm/machine/state/TsState.kt	Introduce method2ref/associatedMethods maps and getMethodRef
usvm-ts/src/main/kotlin/org/usvm/machine/state/TsMethodResult.kt	Change Success from sealed class to interface
usvm-ts/src/main/kotlin/org/usvm/machine/interpreter/TsInterpreter.kt	Refactor call handling to use mockMethodCall and doWithState
usvm-ts/src/main/kotlin/org/usvm/machine/expr/TsExprResolver.kt	Implement visit(EtsPtrCallExpr) and enhance field-ref logic
usvm-ts/src/main/kotlin/org/usvm/machine/expr/TsSimpleValueResolver.kt	Resolve anonymous-method locals and register pointer refs
usvm-ts/src/main/kotlin/org/usvm/machine/TsMethodCall.kt	Change instance from nullable to non-nullable
usvm-ts/src/main/kotlin/org/usvm/api/TsMock.kt	Add mockMethodCall helper function

Comments suppressed due to low confidence (2)

usvm-ts/src/main/kotlin/org/usvm/machine/state/TsState.kt:62

• [nitpick] The property name 'method2ref' is ambiguous; consider renaming it to 'methodToRefMap' for clarity.

    var method2ref: UPersistentHashMap<EtsMethod, UConcreteHeapRef> = persistentHashMapOf(),

usvm-ts/src/main/kotlin/org/usvm/machine/state/TsState.kt:63

• [nitpick] The property name 'associatedMethods' is not descriptive of its mapping direction; consider renaming it to 'refToMethodMap'.

    var associatedMethods: UPersistentHashMap<UConcreteHeapRef, EtsMethod> = persistentHashMapOf(),