Drop identityEquals from builtins, compiler and tests.

compiler/testData/codegen/boxWithStdlib/arrays/clonePrimitiveArrays.kt

@@ -3,35 +3,35 @@ import java.util.Arrays.equals
 fun box(): String {
     val i = intArrayOf(1, 2)
     if (!equals(i, i.clone())) return "Fail int"
-    if (i.clone().identityEquals(i)) return "Fail int identity"
+    if (i.clone() === i) return "Fail int identity"
 
     val j = longArrayOf(1L, 2L)
     if (!equals(j, j.clone())) return "Fail long"
-    if (j.clone().identityEquals(j)) return "Fail long identity"
+    if (j.clone() === j) return "Fail long identity"
 
     val s = shortArrayOf(1.toShort(), 2.toShort())
     if (!equals(s, s.clone())) return "Fail short"
-    if (s.clone().identityEquals(s)) return "Fail short identity"
+    if (s.clone() === s) return "Fail short identity"
 
     val b = byteArrayOf(1.toByte(), 2.toByte())
     if (!equals(b, b.clone())) return "Fail byte"
-    if (b.clone().identityEquals(b)) return "Fail byte identity"
+    if (b.clone() === b) return "Fail byte identity"
 
     val c = charArrayOf('a', 'b')
     if (!equals(c, c.clone())) return "Fail char"
-    if (c.clone().identityEquals(c)) return "Fail char identity"
+    if (c.clone() === c) return "Fail char identity"
 
     val d = doubleArrayOf(1.0, -1.0)
     if (!equals(d, d.clone())) return "Fail double"
-    if (d.clone().identityEquals(d)) return "Fail double identity"
+    if (d.clone() === d) return "Fail double identity"
 
     val f = floatArrayOf(1f, -1f)
     if (!equals(f, f.clone())) return "Fail float"
-    if (f.clone().identityEquals(f)) return "Fail float identity"
+    if (f.clone() === f) return "Fail float identity"
 
     val z = booleanArrayOf(true, false)
     if (!equals(z, z.clone())) return "Fail boolean"
-    if (z.clone().identityEquals(z)) return "Fail boolean identity"
+    if (z.clone() === z) return "Fail boolean identity"
 
     return "OK"
 }