fix build stuff

libc.h

@@ -1,10 +1,12 @@
 #ifndef UNDAR_LIBC_H
 #define UNDAR_LIBC_H
-
 #if defined(__has_include)
 #if __has_include(<stdint.h>)
 #define HAVE_STDINT 1
 #endif
+#if __has_include(<stdbool.h>) && !defined(__EMSCRIPTEN__)
+#define HAVE_STDBOOL 1
+#endif
 #if __has_include(<stddef.h>)
 #define HAVE_STDDEF 1
 #endif
@@ -31,9 +33,13 @@ typedef signed int r32;
 typedef float f32;
 #endif
 
+#ifdef HAVE_STDBOOL
+#include <stdbool.h>
+#else
 #define true 1
 #define false 0
 typedef u8 bool;
+#endif
 
 #ifdef HAVE_STDDEF
 #include <stddef.h>