rtld(1): Do booleans like C99

Reviewed by:	kib, rlibby
Differential Revision:	https://reviews.freebsd.org/D22964

libexec/rtld-elf/rtld.h

@@ -37,6 +37,7 @@
 #include <elf-hints.h>
 #include <link.h>
 #include <stdarg.h>
+#include <stdbool.h>
 #include <setjmp.h>
 #include <stddef.h>
 
@@ -46,11 +47,6 @@
 #define NEW(type)	((type *) xmalloc(sizeof(type)))
 #define CNEW(type)	((type *) xcalloc(1, sizeof(type)))
 
-/* We might as well do booleans like C++. */
-typedef unsigned char bool;
-#define false	0
-#define true	1
-
 extern size_t tls_last_offset;
 extern size_t tls_last_size;
 extern size_t tls_static_space;