Added tests.

tests/cases/conformance/types/typeRelationships/matchable/equalityWithUnionTypes01.ts

@@ -0,0 +1,20 @@
+interface I1 {
+    p1: number
+}
+
+interface I2 extends I1 {
+    p2: number;
+}
+
+var x = { p1: 10, p2: 20 };
+var y: number | I2 = x;
+var z: I1 = x;
+
+if (y === z || z === y) {
+}
+else if (y !== z || z !== y) {
+}
+else if (y == z || z == y) {
+}
+else if (y != z || z != y) {
+}

tests/cases/conformance/types/typeRelationships/matchable/switchCaseWithUnionTypes01.ts

@@ -0,0 +1,25 @@
+
+var strOrNum: string | number;
+var numOrBool: number | boolean;
+var str: string;
+var num: number;
+var bool: boolean;
+
+switch (strOrNum) {
+    // Identical
+    case strOrNum:
+        break;
+
+    // Constituents
+    case str:
+    case num:
+        break;
+
+    // Overlap in constituents
+    case numOrBool:
+        break;
+
+    // No relation
+    case bool:
+        break;
+}

tests/cases/conformance/types/typeRelationships/matchable/typeAssertionsWithUnionTypes01.ts

@@ -0,0 +1,16 @@
+interface I1 {
+    p1: number
+}
+
+interface I2 extends I1 {
+    p2: number;
+}
+
+var x = { p1: 10, p2: 20 };
+var y: number | I2 = x;
+var z: I1 = x;
+
+var a = <number | I2>z;
+var b = <number>z;
+var c = <I2>z;
+var d = <I1>y;