libstdc++: Update __cpp_lib_concepts value

	* include/std/functional (__cpp_lib_concepts): Update macro value to
	indicate P1964R2 support.
	* include/std/version (__cpp_lib_concepts): Likewise.
	* testsuite/std/concepts/1.cc: Adjust expected value.
	* testsuite/std/concepts/2.cc: Likewise.

libstdc++-v3/ChangeLog

 2020-04-22  Jonathan Wakely  <jwakely@redhat.com>
 
+	* include/std/functional (__cpp_lib_concepts): Update macro value to
+	indicate P1964R2 support.
+	* include/std/version (__cpp_lib_concepts): Likewise.
+	* testsuite/std/concepts/1.cc: Adjust expected value.
+	* testsuite/std/concepts/2.cc: Likewise.
+
 	* include/std/functional (__cpp_lib_constexpr_invoke): Rename to
 	__cpp_lib_constexpr_functional.
 	* include/std/version (__cpp_lib_constexpr_invoke): Likewise.

libstdc++-v3/include/std/concepts

@@ -47,7 +47,7 @@ namespace std _GLIBCXX_VISIBILITY(default)
 {
 _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
-#define __cpp_lib_concepts 201806L
+#define __cpp_lib_concepts 202002L
 
   // [concepts.lang], language-related concepts
 

libstdc++-v3/include/std/version

@@ -168,7 +168,7 @@
 #define __cpp_lib_bounded_array_traits 201902L
 // __cpp_lib_char8_t is defined in <bits/c++config.h>
 #if __cpp_concepts >= 201907L
-# define __cpp_lib_concepts 201806L
+# define __cpp_lib_concepts 202002L
 #endif
 #if __cpp_impl_destroying_delete
 # define __cpp_lib_destroying_delete 201806L

libstdc++-v3/testsuite/std/concepts/1.cc

@@ -22,6 +22,6 @@
 
 #ifndef __cpp_lib_concepts
 # error "Feature test macro for concepts is missing in <concepts>"
-#elif __cpp_lib_concepts < 201806L
+#elif __cpp_lib_concepts < 202002L
 # error "Feature test macro for concepts has wrong value in <concepts>"
 #endif

libstdc++-v3/testsuite/std/concepts/2.cc

@@ -22,6 +22,6 @@
 
 #ifndef __cpp_lib_concepts
 # error "Feature test macro for concepts is missing in <version>"
-#elif __cpp_lib_concepts < 201806L
+#elif __cpp_lib_concepts < 202002L
 # error "Feature test macro for concepts has wrong value in <version>"
 #endif