Add ir interpreter tests

compiler/testData/ir/interpreter/proxy/customEquals.kt

@@ -0,0 +1,13 @@
+import kotlin.collections.*
+
+@CompileTimeCalculation
+class B(val b: Int) {
+    override fun equals(other: Any?): Boolean {
+        other as? B ?: return false
+        return this.b == other.b
+    }
+
+    override fun toString(): String = "B($b)"
+}
+const val areEquals = <!EVALUATED: `true`!>listOf(B(1), B(2)) == listOf(B(1), B(2))<!>
+const val asString = listOf(B(1), B(2)).<!EVALUATED: `[B(1), B(2)]`!>toString()<!>