[Native] Enable linkViaSignatures for K2/Native compiler

Setting `linkViaSignatures = false` leads to the situation when fir2ir
  provides no guarantees about how SymbolTable is filled, so if some
  backend relies on symbol table content (JS and Native does) then
  it's required to set this flag to `true`

The issue was uncovered by previous commits because previously fir2ir
  created symbols with signatures for some declarations even with
  disabled flag, which was fixed by those commits

kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/Fir2Ir.kt

@@ -96,7 +96,7 @@ internal fun PhaseContext.fir2Ir(
     val fir2IrConfiguration = Fir2IrConfiguration(
             languageVersionSettings = configuration.languageVersionSettings,
             diagnosticReporter = diagnosticsReporter,
-            linkViaSignatures = false,
+            linkViaSignatures = true,
             evaluatedConstTracker = configuration
                     .putIfAbsent(CommonConfigurationKeys.EVALUATED_CONST_TRACKER, EvaluatedConstTracker.create()),
             inlineConstTracker = null,