Add ir interpreter tests

compiler/testData/ir/interpreter/branches.kt

@@ -0,0 +1,65 @@
+@CompileTimeCalculation fun ifGreaterOrEqualToZero(a: Int): Boolean {
+    return if (a >= 0) {
+        true
+    } else {
+        false
+    }
+}
+
+@CompileTimeCalculation fun whenGreaterOrEqualToZero(a: Int): Boolean {
+    return when {
+        a >= 0 -> true
+        else -> false
+    }
+}
+
+@CompileTimeCalculation fun whenMultiBranch(a: Int): Int {
+    return when (a) {
+        1 -> -1
+        2 -> -2
+        3 -> -3
+        4 -> -4
+        else -> 0
+    }
+}
+
+class A @CompileTimeCalculation constructor(@CompileTimeCalculation var a: Int)
+
+@CompileTimeCalculation fun whenWithoutReturn(aObj: A): Int {
+    when (aObj.a) {
+        1 -> aObj.a = -1
+        2 -> aObj.a = -2
+        3 -> aObj.a = -3
+        4 -> aObj.a = -4
+        else -> aObj.a = 0
+    }
+
+    return aObj.a
+}
+
+@CompileTimeCalculation fun whenWithoutElse(aObj: A): Int {
+    when (aObj.a) {
+        1 -> aObj.a = -1
+        2 -> aObj.a = -2
+        3 -> aObj.a = -3
+        4 -> aObj.a = -4
+    }
+
+    return aObj.a
+}
+
+const val a = <!EVALUATED: `true`!>ifGreaterOrEqualToZero(10)<!>
+const val b = <!EVALUATED: `false`!>whenGreaterOrEqualToZero(-10)<!>
+const val constIf = <!EVALUATED: `True`!>if (a == true) "True" else "False"<!>
+
+const val multi1 = <!EVALUATED: `-2`!>whenMultiBranch(2)<!>
+const val multi2 = <!EVALUATED: `-4`!>whenMultiBranch(4)<!>
+const val multi3 = <!EVALUATED: `0`!>whenMultiBranch(10)<!>
+
+const val c1 = <!EVALUATED: `-1`!>whenWithoutReturn(A(1))<!>
+const val c2 = <!EVALUATED: `-3`!>whenWithoutReturn(A(3))<!>
+const val c3 = <!EVALUATED: `0`!>whenWithoutReturn(A(10))<!>
+
+const val d1 = <!EVALUATED: `-1`!>whenWithoutElse(A(1))<!>
+const val d2 = <!EVALUATED: `-4`!>whenWithoutElse(A(4))<!>
+const val d3 = <!EVALUATED: `10`!>whenWithoutElse(A(10))<!>