Don't hardcode the Czech locale name.

We already have a definition for the Czech locale name in
platform_support.h. Use this one instead.

While there, respect the common format of the tests. For most other
tests it's the case that test_iterators.h is placed right underneath the
other #includes (without an empty line). platform_support.h is included
after an empty line.

llvm-svn: 232383
diff --git a/libcxx/test/std/re/re.alg/re.alg.search/extended.pass.cpp b/libcxx/test/std/re/re.alg/re.alg.search/extended.pass.cpp
index a8a121b..81eef2f 100644
--- a/libcxx/test/std/re/re.alg/re.alg.search/extended.pass.cpp
+++ b/libcxx/test/std/re/re.alg/re.alg.search/extended.pass.cpp
@@ -23,9 +23,10 @@
 
 #include <regex>
 #include <cassert>
-
 #include "test_iterators.h"
 
+#include "platform_support.h" // locale name macros
+
 int main()
 {
     {
@@ -689,7 +690,7 @@
                                                  std::regex_constants::extended)));
         assert(m.size() == 0);
     }
-    std::locale::global(std::locale("cs_CZ.ISO8859-2"));
+    std::locale::global(std::locale(LOCALE_cs_CZ_ISO8859_2));
     {
         std::cmatch m;
         const char s[] = "m";
@@ -1445,7 +1446,7 @@
                                                  std::regex_constants::extended)));
         assert(m.size() == 0);
     }
-    std::locale::global(std::locale("cs_CZ.ISO8859-2"));
+    std::locale::global(std::locale(LOCALE_cs_CZ_ISO8859_2));
     {
         std::wcmatch m;
         const wchar_t s[] = L"m";