JVM IR: don't rename fake overrides for fields

In case derived class has a field with the same name as the base class,
RenameFieldsLowering previously tried to rename one of the fields by
adding the "...$1" suffix, which led to NoSuchFieldError.

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/RenameFieldsLowering.kt

@@ -96,7 +96,9 @@ private class FieldNameCollector : IrElementVisitorVoid {
     }
 
     override fun visitField(declaration: IrField) {
-        nameToField.getOrPut(declaration.parent to declaration.name) { mutableListOf() }.add(declaration)
+        if (!declaration.isFakeOverride) {
+            nameToField.getOrPut(declaration.parent to declaration.name) { mutableListOf() }.add(declaration)
+        }
     }
 }