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

compiler/testData/codegen/box/reflection/mapping/constructorWithInlineClassParameters.kt

@@ -0,0 +1,21 @@
+// IGNORE_BACKEND: JVM_IR, JS_IR, JS, NATIVE
+// WITH_REFLECT
+import kotlin.reflect.full.primaryConstructor
+import kotlin.reflect.jvm.javaConstructor
+import kotlin.reflect.jvm.kotlinFunction
+import kotlin.test.assertEquals
+
+inline class Z(val x: Int)
+
+class Test(val x: Z)
+
+fun box(): String {
+    val kctor1 = Test::class.primaryConstructor ?: throw AssertionError("No primary constructor")
+    val jctor1 = kctor1.javaConstructor ?: throw AssertionError("No javaConstructor for $kctor1")
+    val kctor2 = jctor1.kotlinFunction ?: throw AssertionError("No kotlinFunction for $jctor1")
+
+    assertEquals(kctor1, kctor2)
+    assertEquals("[x]", kctor2.parameters.map { it.name }.toString())
+
+    return "OK"
+}