K2: resolve remove(Int) clash in JavaOverrideChecker

In Kotlin subclasses of `MutableCollection<Int>`, the method
`remove(Int)` has its argument boxed, so that it wouldn't clash with the
method from `java.util.List`. So `JavaOverrideChecker` should understand
that a Java method `boolean remove(java.lang.Integer)` overrides it,
otherwise platform declaration clash was reported.

The code is adapted from `forceSingleValueParameterBoxing` in K1's
`methodSignatureMapping.kt`.

The test has been moved and adapted from diagnostic to codegen box
tests, to check correct backend execution + runtime.

 #KT-62316 Fixed

compiler/testData/codegen/box/collections/removeAtIntOverrideInJava.kt

@@ -0,0 +1,59 @@
+// TARGET_BACKEND: JVM
+
+// FILE: A.java
+abstract public class A extends B {
+    public Integer removeAt(int x) { return 0; }
+    public boolean remove(Integer x) { return false; }
+}
+
+// FILE: main.kt
+import java.util.*;
+
+abstract class B : MutableList<Int>, AbstractList<Int>() {
+    override fun removeAt(index: Int): Int = null!!
+    override fun remove(element: Int): Boolean = null!!
+}
+
+abstract class D : AbstractList<Int>() {
+    // removeAt() doesn't exist in java/util/AbstractList, it's a
+    // fake override of the method from kotlin/collections/MutableList
+    override fun removeAt(index: Int): Int = 0
+    // AbstractList::remove() should return Int here. No fake overrides created.
+    // This may be a bug because the old compiler doesn't report a diagnostic here.
+    override fun remove(element: Int): Boolean = false
+}
+
+fun testABD(a: A, b: B, d: D) {
+    a.remove(1)
+    a.removeAt(0)
+    b.remove(1)
+    b.removeAt(0)
+    d.remove(1)
+    d.removeAt(0)
+}
+
+fun testArrayList(c: ArrayList<Int>) {
+    c.remove(1)
+    c.removeAt(0)
+}
+
+class AImpl : A() {
+    override fun get(index: Int): Int = 0
+    override val size: Int get() = 0
+}
+
+class DImpl : D() {
+    override fun get(index: Int): Int = 0
+    override val size: Int get() = 0
+}
+
+fun box(): String {
+    testABD(AImpl(), AImpl(), DImpl())
+
+    val c = ArrayList<Int>()
+    c.add(1)
+    c.add(1)
+    testArrayList(c)
+
+    return "OK"
+}