utils: add macro for assume

Clang and GCC allow to provide hints to the compiler, they have similar
constructs but they have a different syntax (builtin VS attribute).

Add portable macro for it.

Signed-off-by: Davide Bettio <davide@uninstall.it>

Author: bettio

src/libAtomVM/utils.h

@@ -327,6 +327,26 @@ static inline __attribute__((always_inline)) func_ptr_t cast_void_to_func_ptr(vo
     #define UNREACHABLE(...)
 #endif
 
+#if defined(__GNUC__) && !defined(__clang__)
+#if __GNUC__ >= 13
+#define HAVE_ASSUME 1
+#define ASSUME(x) __attribute__((assume((x))))
+#endif
+#endif
+
+#ifndef HAVE_ASSUME
+#if defined __has_builtin
+#if __has_builtin(__builtin_assume)
+#define HAVE_ASSUME 1
+#define ASSUME(x) __builtin_assume((x))
+#endif
+#endif
+#endif
+
+#ifndef ASSUME
+#define ASSUME(...)
+#endif
+
 #ifdef __cplusplus
 }
 #endif