Fir2Ir: build fake overrides for abstract methods from Any

This call to isAbstractMethodOfAny was in Fir2IrLazyClass since its
inception in 0622be14a5, and there's no explanation why this was
necessary. Removing it does not seem to break anything, but fixes the
case when IrFakeOverrideRebuilder is enabled and when Java base class
declares an abstract equals/hashCode/toString which is not overridden in
the Kotlin subclass.

 #KT-63443 Fixed

compiler/testData/codegen/box/javaInterop/abstractMethodsOfAny.kt

@@ -0,0 +1,63 @@
+// TARGET_BACKEND: JVM
+// FILE: JI.java
+public interface JI {
+    @Override
+    public abstract boolean equals(Object o);
+    @Override
+    public abstract int hashCode();
+    @Override
+    public abstract String toString();
+}
+
+// FILE: JC.java
+public abstract class JC {
+    @Override
+    public abstract boolean equals(Object o);
+    @Override
+    public abstract int hashCode();
+    @Override
+    public abstract String toString();
+}
+
+// FILE: JC2.java
+public abstract class JC2 extends JC {
+}
+
+// FILE: box.kt
+
+interface KI : JI
+class X : KI {
+    override fun equals(other: Any?): Boolean = true
+    override fun hashCode(): Int = 0
+    override fun toString(): String = ""
+}
+
+abstract class KC : JC()
+class Y : KC() {
+    override fun equals(other: Any?): Boolean = true
+    override fun hashCode(): Int = 0
+    override fun toString(): String = ""
+}
+
+abstract class KC2 : JC2()
+class Z : KC2() {
+    override fun equals(other: Any?): Boolean = true
+    override fun hashCode(): Int = 0
+    override fun toString(): String = ""
+}
+
+fun box(): String {
+    X().equals(X())
+    X().hashCode()
+    X().toString()
+
+    Y().equals(Y())
+    Y().hashCode()
+    Y().toString()
+
+    Z().equals(Z())
+    Z().hashCode()
+    Z().toString()
+
+    return "OK"
+}