Add ir interpreter tests

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

@@ -0,0 +1,8 @@
+import kotlin.*
+import kotlin.collections.*
+
+@CompileTimeCalculation
+class A(val a: Int)
+const val size = mapOf(1 to "A(1)").<!EVALUATED: `1`!>size<!>
+const val first = mapOf(1 to "A(1)").entries.single().<!EVALUATED: `1`!>key<!>
+const val second = mapOf(1 to "A(1)").values.<!EVALUATED: `A(1)`!>single()<!>