Implement kotlin.jvm.overloads annotation for generating all overloads of a method that has default parameter values.

#KT-2095 Fixed

fix backend-side issues with kotlin.jvm.overloads: support the annotation on constructors, generate nullablity annotations on parameters, generate generic signatures, add various tests

compiler/testData/codegen/boxWithStdlib/jvmOverloads/primaryConstructor.kt

@@ -0,0 +1,8 @@
+class C [kotlin.jvm.overloads] (s1: String, s2: String = "K") {
+    public val status: String = s1 + s2
+}
+
+fun box(): String {
+    val c = (javaClass<C>().getConstructor(javaClass<String>()).newInstance("O"))
+    return c.status
+}