feat(compiler): use typescript for resolving resource paths

This can also be customized via the new method `resourceNameToFileName` in the
`CompilerHost`.

packages/compiler/src/aot/compiler_host.ts

@@ -14,6 +14,11 @@ import {AotSummaryResolverHost} from './summary_resolver';
  * services and from underlying file systems.
  */
 export interface AotCompilerHost extends StaticSymbolResolverHost, AotSummaryResolverHost {
+  /**
+   * Converts a path that refers to a resource into an absolute filePath
+   * that can be later on used for loading the resource via `loadResource.
+   */
+  resourceNameToFileName(resourceName: string, containingFileName: string): string|null;
   /**
    * Loads a resource (e.g. html / css)
    */