Use emptyArray, rather than []

Author: amcasey

src/compiler/program.ts

@@ -1071,8 +1071,8 @@ namespace ts {
                 Debug.assert(!!sourceFile.bindDiagnostics);
                 // For JavaScript files, we don't want to report semantic errors unless explicitly requested.
                 const includeBindAndCheckDiagnostics = !isSourceFileJavaScript(sourceFile) || isCheckJsEnabledForFile(sourceFile, options);
-                const bindDiagnostics = includeBindAndCheckDiagnostics ? sourceFile.bindDiagnostics : [];
-                const checkDiagnostics = includeBindAndCheckDiagnostics ? typeChecker.getDiagnostics(sourceFile, cancellationToken) : [];
+                const bindDiagnostics = includeBindAndCheckDiagnostics ? sourceFile.bindDiagnostics : emptyArray;
+                const checkDiagnostics = includeBindAndCheckDiagnostics ? typeChecker.getDiagnostics(sourceFile, cancellationToken) : emptyArray;
                 const fileProcessingDiagnosticsInFile = fileProcessingDiagnostics.getDiagnostics(sourceFile.fileName);
                 const programDiagnosticsInFile = programDiagnostics.getDiagnostics(sourceFile.fileName);