[FIR] Generate signatures for synthesized class delegation fields

This is to align the behavior with K1.

^KT-57754 Fixed

Co-authored-by: Alexander Udalov <alexander.udalov@jetbrains.com>

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/signaturer/FirBasedSignatureComposer.kt

@@ -95,7 +95,6 @@ class FirBasedSignatureComposer(override val mangler: FirMangler) : Fir2IrSignat
         if (declaration is FirRegularClass && declaration.classId.isLocal) return null
         if (declaration is FirCallableDeclaration) {
             if (declaration.visibility == Visibilities.Local) return null
-            if (declaration is FirField && declaration.source?.kind == KtFakeSourceElementKind.ClassDelegationField) return null
             if (declaration.dispatchReceiverClassLookupTagOrNull()?.classId?.isLocal == true || containingClass?.classId?.isLocal == true) return null
         }