include/types.h: conditionally define bool, false and true

include/types.h typedefs 'bool' and macro-defines 'false' and 'true'.
However, since C23, these are predefine keywords. As C23 is the default
C dialect for GCC 15, building with this compiler fails with:

    include/types.h:23:23: error: 'bool' cannot be defined via 'typedef'
       23 | typedef unsigned char bool;
          |                       ^~~~
    include/types.h:23:23: note: 'bool' is a keyword with '-std=c23' onwards

Fix this build failure by only defining 'bool', 'false' and 'true' on C
dialects older than C23.

Signed-off-by: Edgar Bonet <[email protected]>
Signed-off-by: Li Bin <[email protected]>
Acked-by: Nicolas Ferre <[email protected]>

Author: edgar-bonet

include/types.h

@@ -20,8 +20,11 @@ typedef signed long long s64;
 typedef unsigned long size_t;
 typedef signed long ssize_t;
 
+/* bool, false and true are predefined since C23. */
+#if __STDC_VERSION__ < 202311L
 typedef unsigned char bool;
 #define false	0U
 #define true	1U
+#endif
 
 #endif /* TYPES_H_ */