Return kotlin ctor mapped to a java ctor even if java ctor is synthetic

This allows working with constructors with inline class parameters using
Kotlin reflection, as described in
https://youtrack.jetbrains.com/issue/KT-27429#focus=streamItem-27-3161148-0-0

 #KT-27913
 #KT-27429

core/reflection.jvm/src/kotlin/reflect/jvm/ReflectJvmMapping.kt

@@ -144,7 +144,5 @@ val Method.kotlinFunction: KFunction<*>?
  */
 val <T : Any> Constructor<T>.kotlinFunction: KFunction<T>?
     get() {
-        if (isSynthetic) return null
-
         return declaringClass.kotlin.constructors.firstOrNull { it.javaConstructor == this }
     }