Fix failing tests for use of non-reserved names

Defining 'ptr' fails on Solaris because it's used in <netdb.h>.

Including the Filesystem TS header fails if the TS support wasn't
enabled by configure.

	* testsuite/17_intro/names.cc: Do not check 'ptr' on Solaris.
	* testsuite/experimental/names.cc: Include <experimental/filesystem>
	conditionally.

From-SVN: r271421

libstdc++-v3/ChangeLog

 2019-05-20  Jonathan Wakely  <jwakely@redhat.com>
 
+	* testsuite/17_intro/names.cc: Do not check 'ptr' on Solaris.
+	* testsuite/experimental/names.cc: Include <experimental/filesystem>
+	conditionally.
+
 	PR c++/90532 Ensure __is_constructible(T[]) is false
 	* include/std/type_traits (__do_is_default_constructible_impl)
 	(__is_default_constructible_atom, __is_default_constructible_safe):

libstdc++-v3/testsuite/17_intro/names.cc

@@ -187,4 +187,9 @@
 #undef y
 #endif
 
+#ifdef __sun__
+// See https://gcc.gnu.org/ml/libstdc++/2019-05/msg00175.html
+#undef ptr
+#endif
+
 #include <bits/stdc++.h>

libstdc++-v3/testsuite/experimental/names.cc

@@ -22,7 +22,9 @@
 
 #include "../17_intro/names.cc"
 // Filesystem
-#include <experimental/filesystem>
+#if __has_include(<experimental/filesystem>)
+# include <experimental/filesystem>
+#endif
 // Library Fundamentals
 #include <experimental/algorithm>
 #include <experimental/any>