[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/charsequence/javaCharSequenceOverride.fir.kt.txt

@@ -0,0 +1,238 @@
+class B : A {
+  constructor() /* primary */ {
+    super/*Any*/()
+    /* <init>() */
+
+  }
+
+  override fun charAt(index: Int): Char {
+    return '1'
+  }
+
+  override fun length(): Int {
+    return 1
+  }
+
+  override fun subSequence(start: Int, end: Int): CharSequence {
+    return CHECK_NOT_NULL<Nothing>(arg0 = null)
+  }
+
+}
+
+class C : Java1 {
+  constructor() /* primary */ {
+    super/*Java1*/()
+    /* <init>() */
+
+  }
+
+}
+
+class D : Java1 {
+  constructor() /* primary */ {
+    super/*Java1*/()
+    /* <init>() */
+
+  }
+
+  override operator fun get(index: Int): Char {
+    return 'a'
+  }
+
+  override val length: Int
+    override get(): Int {
+      return 10
+    }
+
+}
+
+class E : Java1, Java2 {
+  constructor() /* primary */ {
+    super/*Java1*/()
+    /* <init>() */
+
+  }
+
+  override fun codePoints(): IntStream {
+    return CHECK_NOT_NULL<Nothing>(arg0 = null)
+  }
+
+}
+
+class F : Java1, KotlinInterface {
+  constructor() /* primary */ {
+    super/*Java1*/()
+    /* <init>() */
+
+  }
+
+  override operator fun get(index: Number): Char {
+    return 'a'
+  }
+
+}
+
+class G : Java1, KotlinInterface {
+  constructor() /* primary */ {
+    super/*Java1*/()
+    /* <init>() */
+
+  }
+
+  override operator fun get(index: Int): Char {
+    return 'a'
+  }
+
+  override operator fun get(index: Number): Char {
+    return 'b'
+  }
+
+}
+
+class H : Java1, Java2, KotlinInterface {
+  constructor() /* primary */ {
+    super/*Java1*/()
+    /* <init>() */
+
+  }
+
+  override fun codePoints(): IntStream {
+    return CHECK_NOT_NULL<Nothing>(arg0 = null)
+  }
+
+  override operator fun get(index: Number): Char {
+    return 'a'
+  }
+
+}
+
+class I : Java1, Java2, Java3 {
+  constructor() /* primary */ {
+    super/*Java1*/()
+    /* <init>() */
+
+  }
+
+  override fun codePoints(): IntStream {
+    return CHECK_NOT_NULL<Nothing>(arg0 = null)
+  }
+
+}
+
+abstract class J : Java4 {
+  constructor() /* primary */ {
+    super/*Java4*/()
+    /* <init>() */
+
+  }
+
+}
+
+class K : Java4 {
+  constructor() /* primary */ {
+    super/*Java4*/()
+    /* <init>() */
+
+  }
+
+  override fun charAt(index: Int): Char {
+    return 'a'
+  }
+
+  override fun length(): Int {
+    return 1
+  }
+
+  override fun subSequence(start: Int, end: Int): CharSequence {
+    return CHECK_NOT_NULL<Nothing>(arg0 = null)
+  }
+
+}
+
+abstract class L : Java1, A {
+  constructor() /* primary */ {
+    super/*Java1*/()
+    /* <init>() */
+
+  }
+
+  override fun chars(): IntStream {
+    return CHECK_NOT_NULL<Nothing>(arg0 = null)
+  }
+
+  override fun codePoints(): IntStream {
+    return CHECK_NOT_NULL<Nothing>(arg0 = null)
+  }
+
+}
+
+abstract class M : Java1, CharSequence {
+  constructor() /* primary */ {
+    super/*Java1*/()
+    /* <init>() */
+
+  }
+
+  override fun chars(): IntStream {
+    return CHECK_NOT_NULL<Nothing>(arg0 = null)
+  }
+
+  override fun codePoints(): IntStream {
+    return CHECK_NOT_NULL<Nothing>(arg0 = null)
+  }
+
+}
+
+interface A : CharSequence {
+}
+
+interface KotlinInterface {
+  abstract fun get(index: Number): Char
+
+  abstract val length: Number
+    abstract get
+
+}
+
+fun test(a: A, b: B, c: C, d: D, e: E, f: F, g: G, h: H, i: I, j: J, k: K, l: L, m: M) {
+  a.length() /*~> Unit */
+  a.charAt(p0 = 1) /*~> Unit */
+  a.chars() /*~> Unit */
+  a /*as Any */.toString() /*~> Unit */
+  b.length() /*~> Unit */
+  b.charAt(index = 1) /*~> Unit */
+  b.subSequence(start = 1, end = 2) /*~> Unit */
+  c.<get-length>() /*~> Unit */
+  c.get(index = 1) /*~> Unit */
+  c.chars() /*~> Unit */
+  d.<get-length>() /*~> Unit */
+  d.get(index = 1) /*~> Unit */
+  d.isEmpty() /*~> Unit */
+  e.<get-length>() /*~> Unit */
+  e.get(index = 1) /*~> Unit */
+  e.isEmpty() /*~> Unit */
+  e.codePoints() /*~> Unit */
+  f.<get-length>() /*~> Unit */
+  f.isEmpty() /*~> Unit */
+  f.get(index = 1) /*~> Unit */
+  g.<get-length>() /*~> Unit */
+  g.get(index = 1) /*~> Unit */
+  h.<get-length>() /*~> Unit */
+  h.get(index = 1) /*~> Unit */
+  h.codePoints() /*~> Unit */
+  i.<get-length>() /*~> Unit */
+  i.isEmpty() /*~> Unit */
+  i.get(index = 1) /*~> Unit */
+  i.codePoints() /*~> Unit */
+  j.length() /*~> Unit */
+  j.charAt(p0 = 1) /*~> Unit */
+  k.charAt(index = 1) /*~> Unit */
+  k.length() /*~> Unit */
+  l.<get-length>() /*~> Unit */
+  l.get(index = 1) /*~> Unit */
+  l.length() /*~> Unit */
+  m.<get-length>() /*~> Unit */
+  m.length() /*~> Unit */
+  m.get(index = 1) /*~> Unit */
+  m.get(index = 1) /*~> Unit */
+}