Issue #13441: Skip some locales (e.g. cs_CZ and hu_HU) on Solaris to workaround

a mbstowcs() bug. For example, on Solaris, the hu_HU locale uses the locale
encoding ISO-8859-2, the thousauds separator is b'\xA0' and it is decoded as
U+30000020 (an invalid character) by mbstowcs().

The workaround is not enabled yet (commented): I would like first to get
more information about the failing locales.