Make clangd work with toolchain's headers

src/kernel.c

@@ -1,6 +1,16 @@
-#include "stdio.h"
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+#if defined(__linux__)
+#error "Not using a cross compiler"
+#endif
+
+#if !defined(__i386__)
+#error "Not using the right compiler"
+#endif
 
 int main() {
-    printf("Hello, world!\n");
-    return 0;
+    return 1;
+    return false;
 }