libstdc++: Add test for not using reserved name 'ranges' before C++20

This is a test for a bug that was present on trunk, because 'ranges' is
not a reserved name before C++20.

libstdc++-v3/ChangeLog:

	* testsuite/17_intro/names.cc: Check ranges is not used as an
	identifier before C++20.

diff --git a/libstdc++-v3/testsuite/17_intro/names.cc b/libstdc++-v3/testsuite/17_intro/names.cc
index ab12641b14dfd49a165858a2a94676244e6cc74b..5acbdf38044d86526be4b7bcd9e0e66b1431d564 100644 (file)
--- a/libstdc++-v3/testsuite/17_intro/names.cc
+++ b/libstdc++-v3/testsuite/17_intro/names.cc
@@ -140,6 +140,10 @@
 #define try_emplace (
 #endif
 
+#if __cplusplus < 202002L
+#define ranges (
+#endif
+
 // These clash with newlib so don't use them.
 # define __lockable            cannot be used as an identifier
 # define __null_sentinel       cannot be used as an identifier