refactor, libc made optional

Common/Std/stub.c

@@ -0,0 +1,10 @@
+#include "../std.h"
+
+void *com_std_realloc(void *ptr, size_t size) { return NULL; }
+void com_std_free(void *ptr) {}
+void com_std_assert(bool holds) {}
+void com_std_printf(char const *fmt, ...) {}
+double com_std_sqrt(double v) { return 0; }
+double com_std_fabs(double v) { return 0; }
+double com_std_sin(double v) { return 0; }
+double com_std_cos(double v) { return 0; }