[Test] KT-61360: add tests for the IrFakeOverrideBuilder

Add tests for fake overrides with focus on java interoperability

Co-authored-by: Aleksandra Arsenteva <aleksandra.arsenteva@jetbrains.com>

compiler/testData/ir/irText/fakeOverrides/generics/basicGenericWithBoundsOverride.kt.txt

@@ -0,0 +1,92 @@
+class A : Java1<Int> {
+  constructor() /* primary */ {
+    super/*Java1*/<@FlexibleNullability Int?>()
+    /* <init>() */
+
+  }
+
+}
+
+class B : Java1<Int> {
+  constructor() /* primary */ {
+    super/*Java1*/<@FlexibleNullability Int?>()
+    /* <init>() */
+
+  }
+
+  override fun bar(): Int {
+    return 1
+  }
+
+  override fun foo(t: Int?) {
+  }
+
+}
+
+abstract class C : Java2<Double> {
+  constructor() /* primary */ {
+    super/*Any*/()
+    /* <init>() */
+
+  }
+
+}
+
+class D : Java2<Double> {
+  constructor() /* primary */ {
+    super/*Any*/()
+    /* <init>() */
+
+  }
+
+  override fun bar(): Double {
+    return 1.1
+  }
+
+  override fun foo(t: Double) {
+  }
+
+}
+
+abstract class E : Java3 {
+  constructor() /* primary */ {
+    super/*Any*/()
+    /* <init>() */
+
+  }
+
+}
+
+class F : Java3 {
+  constructor() /* primary */ {
+    super/*Any*/()
+    /* <init>() */
+
+  }
+
+  override fun <U : Number> bar(): U {
+    return CHECK_NOT_NULL<Nothing>(arg0 = null)
+  }
+
+  override fun <U : Number> foo(a: U) {
+  }
+
+}
+
+fun test(a: A, b: B, c: C, d: D, e: E, f: F) {
+  a.foo(t = null)
+  a.foo(t = 1)
+  a.bar() /*~> Unit */
+  b.foo(t = null)
+  b.foo(t = 1)
+  b.bar() /*~> Unit */
+  c.foo(t = null)
+  c.foo(t = 1.1)
+  c.bar() /*~> Unit */
+  d.foo(t = 1.1)
+  d.bar() /*~> Unit */
+  e.foo<@FlexibleNullability Int?>(a = 1)
+  e.bar<@FlexibleNullability Int?>() /*~> Unit */
+  f.foo<Double>(a = 2.2)
+  f.bar<Double>() /*~> Unit */
+}