Added test for goToDef on union types.

tests/cases/fourslash/goToDefinitionUnionTypeProperty4.ts

@@ -0,0 +1,32 @@
+/// <reference path='fourslash.ts' />
+
+////interface SnapCrackle {
+////    /*def1*/pop(): string;
+////}
+////
+////interface Magnitude {
+////    /*def2*/pop(): number;
+////}
+////
+////interface Art {
+////    /*def3*/pop(): boolean;
+////}
+////
+////var art: Art;
+////var magnitude: Magnitude;
+////var snapcrackle: SnapCrackle;
+////
+////var x = (snapcrackle || magnitude || art)./*usage*/pop;
+
+goTo.marker("usage");
+verify.definitionCountIs(3);
+goTo.definition(0);
+verify.caretAtMarker("def1");
+
+goTo.marker("usage");
+goTo.definition(1);
+verify.caretAtMarker("def2");
+
+goTo.marker("usage");
+goTo.definition(2);
+verify.caretAtMarker("def3");