Fix compilation on Mac.

The methods Utils::UnixUtils::fileBrowser and
Utils::UnixUtils::substituteFileBrowserParameters are both declared when
compiling on MacOS, but their implementation is not compiled into
libutils. So this gives linker errors.

Change-Id: I0befb607dda0a83d681068f8236167ba88918460
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>

src/plugins/coreplugin/fileutils.cpp

@@ -104,6 +104,7 @@ void FileUtils::showInGraphicalShell(QWidget *parent, const QString &pathIn)
                    << QLatin1String("tell application \"Finder\" to activate");
         QProcess::execute(QLatin1String("/usr/bin/osascript"), scriptArgs);
     } else {
+#ifndef Q_OS_MAC
         // we cannot select a file here, because no file browser really supports it...
         const QFileInfo fileInfo(pathIn);
         const QString folder = fileInfo.isDir() ? fileInfo.absoluteFilePath() : fileInfo.filePath();
@@ -115,6 +116,7 @@ void FileUtils::showInGraphicalShell(QWidget *parent, const QString &pathIn)
         success = success && error.isEmpty();
         if (!success)
             showGraphicalShellError(parent, app, error);
+#endif
     }
 }