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/boxWithJava/jvmOverloads/generics/Test.java

@@ -0,0 +1,6 @@
+public class Test {
+    public static String invokeMethodWithOverloads() {
+        C<String> c = new C<String>();
+        return c.foo("O");
+    }
+}

compiler/testData/codegen/boxWithJava/jvmOverloads/generics/generics.kt

@@ -0,0 +1,7 @@
+class C<T> {
+    [kotlin.jvm.overloads] public fun foo(o: T, k: String = "K"): String = o.toString() + k
+}
+
+fun box(): String {
+    return Test.invokeMethodWithOverloads()
+}

compiler/testData/codegen/boxWithJava/jvmOverloads/simple/Test.java

@@ -0,0 +1,6 @@
+public class Test {
+    public static String invokeMethodWithOverloads() {
+        C c = new C();
+        return c.foo();
+    }
+}

compiler/testData/codegen/boxWithJava/jvmOverloads/simple/simple.kt

@@ -0,0 +1,7 @@
+class C {
+    [kotlin.jvm.overloads] public fun foo(o: String = "O", k: String = "K"): String = o + k
+}
+
+fun box(): String {
+    return Test.invokeMethodWithOverloads()
+}