[libc++] Fix two fr_FR locale tests on FreeBSD

[arichardson]

Summary

FreeBSD's locale data appears to use the same U+2027 separator as Glibc
2.27 and newer.

[emaste]

This is fine with me; have we always done that?

[arichardson]

In D91165#2385843, @emaste wrote:

This is fine with me; have we always done that?

Looks like the file changed in 2018 (https://github.com/freebsd/freebsd/commit/85d52a26546e940979f91b8ba0b8ac54faa362ad). It works for me on a 12.1-RELEASE-p8 system, I'm not sure if we need to add a runtime check?

[emaste]

I'm not sure if we need to add a runtime check?

I don't think so; I'm not too concerned whether this test passes or not on 11.x and 12.1 is the oldest supported 12.x release at present.
Maybe add a (as of 2018) note in the comment?

libcxx/test/std/localization/locale.categories/category.monetary/locale.money.get/locale.money.get.members/get_long_double_fr_FR.pass.cpp

 class my_facetw
     : public Fw
 {
 public:
     explicit my_facetw(std::size_t refs = 0)
         : Fw(refs) {}
 };
 
-
 // GLIBC 2.27 and newer use U2027 (narrow non-breaking space) as a thousands sep.
 // this function converts the spaces in string inputs to that character if need
-// be.
+// be. FreeBSD's locale data also uses U2027 since 2018.
 static std::wstring convert_thousands_sep(std::wstring const& in) {
+#if defined(_CS_GNU_LIBC_VERSION) || defined(__FreeBSD__)
 #if defined(_CS_GNU_LIBC_VERSION)
   if (glibc_version_less_than("2.27"))
     return in;
+#endif
   std::wstring out;
   unsigned I = 0;
   bool seen_decimal = false;
   for (; I < in.size(); ++I) {
     if (seen_decimal || in[I] != L' ') {
       seen_decimal |= in[I] == L',';
       out.push_back(in[I]);
       continue;

libcxx/test/std/localization/locale.categories/category.monetary/locale.money.put/locale.money.put.members/put_long_double_fr_FR.pass.cpp

 class my_facetw
     : public Fw
 {
 public:
     explicit my_facetw(std::size_t refs = 0)
         : Fw(refs) {}
 };
 
-
 // GLIBC 2.27 and newer use U2027 (narrow non-breaking space) as a thousands sep.
 // this function converts the spaces in string inputs to that character if need
-// be.
+// be. FreeBSD's locale data also uses U2027 since 2018.
 static std::wstring convert_thousands_sep(std::wstring const& in) {
+#if defined(_CS_GNU_LIBC_VERSION) || defined(__FreeBSD__)
 #if defined(_CS_GNU_LIBC_VERSION)
   if (glibc_version_less_than("2.27"))
     return in;
+#endif
   std::wstring out;
   unsigned I = 0;
   bool seen_num_start = false;
   bool seen_decimal = false;
   for (; I < in.size(); ++I) {
     seen_decimal |= in[I] == L',';
     seen_num_start |= in[I] == '-' || std::iswdigit(in[I]);
     if (seen_decimal || !seen_num_start || in[I] != L' ') {