std: use three-way comparison in map test

alib2std/test-src/extensions/container/MapTest.cpp

@@ -31,8 +31,8 @@ namespace {
 			return * this;
 		}
-		bool operator<(const Moveable&) const {
-			return false;
+		auto operator <=> (const Moveable&) const {
+			return std::strong_ordering::equal;
 		}
 	};
 }