[Kotlin] getSignature returns undefined due to getChildByField on fieldless grammar

[hiyizhiyu]

Bug Description

tree-sitter-kotlin does not use field names, but getSignature
calls getChildByField(node, 'function_value_parameters'),
which causes the signature of Kotlin methods to always resolve
to undefined.

Fix

The fix is consistent with extractKotlinReturnType:
replace getChildByField with iteration over namedChildren,
matching the target node by its type property.

[colbymchenry]

Fixed in #1807 (57d9132c), landing upstream #1687 (@danusha2345) onto current main as a Forge PR.

Root cause

tree-sitter-kotlin has no field names, so getSignature via getChildByField('function_value_parameters' / 'type') always missed → every Kotlin function/method had signature: undefined.

Fix

Positional namedChildren read (same pattern as extractKotlinReturnType) in wasm kotlin.ts + kernel signature_of lockstep.

Linux verify (fail → pass)

Symbol	Before	After (wasm + kernel)
greet	undefined	(name: String): String
noReturn	undefined	(x: Int)
topLevel	undefined	(a: Int, b: Int): Int

Undefined signatures 3 → 0; wasm/kernel parity PASS. Focused tests: 31 passed (kernel-kotlin-parity + Kotlin extraction + kernel-scaffold) with CODEGRAPH_KERNEL_EXPECT=1.

Closing as completed. Upstream #1687 will be closed as superseded by #1807.