libc++ buildfix

[jbeich]

Building baka-mplayer with libc++ (on FreeBSD, OS X) fails with

src/ui/mainwindow.cpp:996:53: error: use of undeclared identifier 'ceil'
        playlistRect.setLeft(playlistRect.right() - ceil(playlistRect.width()/7.0));
                                                    ^
1 error generated.

Compare with libstdc++ bootlegging ceil() declaration as follows

In file included from /usr/include/math.h:254:0,
                 from /usr/local/lib/gcc5/include/c++/cmath:44:0,
                 from /usr/local/lib/gcc5/include/c++/random:38,
                 from /usr/local/lib/gcc5/include/c++/bits/stl_algo.h:66,
                 from /usr/local/lib/gcc5/include/c++/algorithm:62,
                 from /usr/local/include/qt5/QtCore/qglobal.h:81,
                 from /usr/local/include/qt5/QtGui/qwindowdefs.h:37,
                 from /usr/local/include/qt5/QtWidgets/qwidget.h:37,
                 from /usr/local/include/qt5/QtWidgets/qmainwindow.h:37,
                 from /usr/local/include/qt5/QtWidgets/QMainWindow:1,
                 from src/ui/mainwindow.h:4,
                 from src/ui/mainwindow.cpp:1:

(discovered by putting #error in math.h)

[godly-devotion]

Thanks!