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

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

mingw-w64-python-scikit-learn/PKGBUILD

@@ -17,7 +17,8 @@ depends=("${MINGW_PACKAGE_PREFIX}-python"
          "${MINGW_PACKAGE_PREFIX}-python-scipy"
          "${MINGW_PACKAGE_PREFIX}-python-joblib")
 makedepends=("${MINGW_PACKAGE_PREFIX}-python-setuptools"
-             "${MINGW_PACKAGE_PREFIX}-cython")
+             "${MINGW_PACKAGE_PREFIX}-cython"
+             "${MINGW_PACKAGE_PREFIX}-cc")
 source=("${_realname}-${pkgver}.tar.gz::https://github.com/scikit-learn/${_realname}/archive/${pkgver}.tar.gz"
         001-mingw-python-openmp-flag.patch
         002-openmp-cleanup-wait.patch)