Make sure every package using a C/C++ compiler depends on one

The "cc" virtual package provides the environment default compiler.

mingw-w64-python-matplotlib/PKGBUILD

@@ -26,7 +26,8 @@ depends=("${MINGW_PACKAGE_PREFIX}-python-pytz"
          "${MINGW_PACKAGE_PREFIX}-qhull")
 makedepends=("${MINGW_PACKAGE_PREFIX}-python"
              "${MINGW_PACKAGE_PREFIX}-python-setuptools"
-             "${MINGW_PACKAGE_PREFIX}-python-certifi")
+             "${MINGW_PACKAGE_PREFIX}-python-certifi"
+             "${MINGW_PACKAGE_PREFIX}-cc")
 optdepends=("${MINGW_PACKAGE_PREFIX}-python-pyqt5: Qt5Agg/Qt5Cairo backend"
             "${MINGW_PACKAGE_PREFIX}-gtk3: GTK3Agg/GTK3Cairo backend"
             "${MINGW_PACKAGE_PREFIX}-python-gobject: GTK3Agg/GTK3Cairo backend"