Adjust test to pass with latest glibc

Glibc changed the it_IT locales to use thousands separators,
invalidating this test. Use nl_NL instead, as Dutch only uses grouping
for money not numbers.

	* testsuite/22_locale/numpunct/members/char/3.cc: Adjust test to
	account for change to glibc it_IT localedata (glibc bz#10797).

From-SVN: r265165

libstdc++-v3/ChangeLog

 2018-10-15  Jonathan Wakely  <jwakely@redhat.com>
 
+	* testsuite/22_locale/numpunct/members/char/3.cc: Adjust test to
+	account for change to glibc it_IT localedata (glibc bz#10797).
+
 	PR libstdc++/87587
 	* src/c++11/cxx11-shim_facets.cc: Suppress -Wabi warnings.
 

libstdc++-v3/testsuite/22_locale/numpunct/members/char/3.cc

-// { dg-require-namedlocale "it_IT.ISO8859-15" }
+// { dg-require-namedlocale "nl_NL.ISO8859-15" }
 
 // 2001-01-24 Benjamin Kosnik  <bkoz@redhat.com>
 
@@ -28,12 +28,14 @@ void test02()
 {
   using namespace std;
 
-  locale loc_it = locale(ISO_8859(15,it_IT));
+  // nl_NL chosen because it has no thousands separator (at this time).
+  locale loc_it = locale(ISO_8859(15,nl_NL));
 
   const numpunct<char>& nump_it = use_facet<numpunct<char> >(loc_it); 
 
   string g = nump_it.grouping();
 
+  // Ensure that grouping is empty for locales with empty thousands separator.
   VERIFY( g == "" );
 }