Fix locale test data for GLIBC 2.27 and newer.

GLIBC 2.27 changed the locale data for fr_FR and ru_RU. In particular
they change the decimal and thousands separators used. This patch
makes the locale tests tolerate the updated locales.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@329143 91177308-0d34-0410-b5e6-96231b3b80d8

src/locale.cpp

@@ -4240,6 +4240,7 @@ static bool checked_string_to_char_convert(char& dest,
   // FIXME: Work around specific multibyte sequences that we can reasonable
   // translate into a different single byte.
   switch (wout) {
+  case L'\u202F': // narrow non-breaking space
   case L'\u00A0': // non-breaking space
     dest = ' ';
     return true;