build/lib/tsb/builder.ts/LanguageServiceHost/getScriptSnapshot
class LanguageServiceHost:	getScriptSnapshot(filename: string, resolve: boolean = true): ScriptSnapshot {
		filename = normalize(filename);
		let result = this._snapshots[filename];
		if (!result && resolve) {
			try {
				result = new VinylScriptSnapshot(new Vinyl(<any>{
					path: filename,
					contents: readFileSync(filename),
					base: this.getCompilationSettings().outDir,
					stat: statSync(filename)
				}));
				this.addScriptSnapshot(filename, result);
			} catch (e) {
				// ignore
			}
		}
		return result;
	}