Add test for find references

src/server/client.ts

@@ -301,7 +301,7 @@ module ts.server {
                 return {
                     fileName: entry.file,
                     textSpan: ts.createTextSpanFromBounds(start, end),
-                    isWriteAccess: false,
+                    isWriteAccess: entry.isWriteAccess,
                 };
             });
         }

src/server/protocol.ts

@@ -409,6 +409,7 @@ module ts.server {
                     start: start,
                     lineText: lineText,
                     end: compilerService.host.positionToLineCol(ref.fileName, ts.textSpanEnd(ref.textSpan)),
+                    isWriteAccess: ref.isWriteAccess
                 };
             }).sort(compareFileStart);
             return {

src/server/protodef.d.ts

@@ -127,6 +127,9 @@ declare module ServerProtocol {
             loaded the referencing files).
         */
         lineText: string;
+
+        /** True if reference is a write location, false otherwise. */
+        isWriteAccess: boolean;
     }
 
     /** The body of a "references" response message. */