Add initial tests

tests/cases/conformance/es2018/dynamicImport/importCallExpression1.ts

@@ -0,0 +1,11 @@
+// @module: es2018
+// @target: esnext
+// @filename: 0.ts
+export function foo() { return "foo"; }
+
+// @filename: 1.ts
+import("./0");
+var p1 = import("./0");
+p1.then(zero => {
+    return zero.foo();
+})

tests/cases/conformance/es2018/dynamicImport/importCallExpression2.ts

@@ -0,0 +1,10 @@
+// @module: es2018
+// @lib: es2015
+// @filename: 0.ts
+export function foo(){}
+
+// @filename: 1.ts
+import * as Zero from "./0"  // Should preserve ES2015 module syntax
+import("./0");
+var p1 = import("./0");
+export default p1;