stage1 assertions always on, and have stack traces

src/util.cpp

@@ -10,17 +10,25 @@
 #include <stdarg.h>
 
 #include "util.hpp"
+#include "userland.h"
 
 void zig_panic(const char *format, ...) {
     va_list ap;
     va_start(ap, format);
     vfprintf(stderr, format, ap);
-    fprintf(stderr, "\n");
     fflush(stderr);
     va_end(ap);
+    stage2_panic(nullptr, 0);
     abort();
 }
 
+void assert(bool ok) {
+    if (!ok) {
+        const char *msg = "Assertion failed. This is a bug in the Zig compiler.";
+        stage2_panic(msg, strlen(msg));
+    }
+}
+
 uint32_t int_hash(int i) {
     return (uint32_t)(i % UINT32_MAX);
 }