Clean up more code

- Found some bugs in LLVM compiler-rt library
- The useless LIBC_STUBS package is now deleted
- Improve the overflow checking story even further
- Get chibicc tests working in MODE=dbg mode again
- The libc/isystem/ headers now have correctly named guards

libc/log/attachdebugger.c

@@ -108,7 +108,7 @@ relegated int(AttachDebugger)(intptr_t continuetoaddr) {
                      "c",      NULL,
                  },
                  environ);
-    __builtin_trap();
+    abort();
   }
   return pid;
 }

libc/log/log.mk

@@ -35,7 +35,6 @@ LIBC_LOG_A_DIRECTDEPS =					\
 	LIBC_RUNTIME					\
 	LIBC_STDIO					\
 	LIBC_STR					\
-	LIBC_STUBS					\
 	LIBC_SYSV					\
 	LIBC_SYSV_CALLS					\
 	LIBC_TIME					\

libc/log/oncrash_amd64.c

@@ -45,6 +45,7 @@
 #include "libc/str/str.h"
 #include "libc/thread/thread.h"
 #include "libc/thread/tls.h"
+#include "libc/str/str.h"
 #include "third_party/libcxx/math.h"
 #ifdef __x86_64__
 
@@ -222,14 +223,14 @@ relegated void ShowCrashReport(int err, int sig, struct siginfo *si,
       p, n,
       "\n%serror%s: Uncaught %G (%s) on %s pid %d tid %d\n"
       "  %s\n"
-      "  %m\n"
+      "  %s\n"
       "  %s %s %s %s\n",
       !__nocolor ? "\e[30;101m" : "", !__nocolor ? "\e[0m" : "", sig,
       (ctx && (ctx->uc_mcontext.rsp >= GetStaticStackAddr(0) &&
                ctx->uc_mcontext.rsp <= GetStaticStackAddr(0) + APE_GUARDSIZE))
           ? "Stack Overflow"
           : GetSiCodeName(sig, si->si_code),
-      host, getpid(), gettid(), program_invocation_name, names.sysname,
+      host, getpid(), gettid(), program_invocation_name, strerror(err), names.sysname,
       names.version, names.nodename, names.release);
   if (ctx) {
     p = ShowGeneralRegisters(p, ctx);
@@ -343,7 +344,7 @@ relegated void __oncrash_amd64(int sig, struct siginfo *si, void *arg) {
     } else {
       // somehow __minicrash() crashed not possible
       for (;;) {
-        __builtin_trap();
+        abort();
       }
     }
   } else {