Pipe through Chakra APIs for tsc.exe --build

Author: RyanCavanaugh

src/compiler/sys.ts

@@ -508,6 +508,9 @@ namespace ts {
         echo(s: string): void;
         quit(exitCode?: number): void;
         fileExists(path: string): boolean;
+        deleteFile(path: string): boolean;
+        getModifiedTime(path: string): Date;
+        setModifiedTime(path: string, time: Date): void;
         directoryExists(path: string): boolean;
         createDirectory(path: string): void;
         resolvePath(path: string): string;
@@ -1135,6 +1138,9 @@ namespace ts {
                 },
                 resolvePath: ChakraHost.resolvePath,
                 fileExists: ChakraHost.fileExists,
+                deleteFile: ChakraHost.deleteFile,
+                getModifiedTime: ChakraHost.getModifiedTime,
+                setModifiedTime: ChakraHost.setModifiedTime,
                 directoryExists: ChakraHost.directoryExists,
                 createDirectory: ChakraHost.createDirectory,
                 getExecutingFilePath: () => ChakraHost.executingFile,