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/x/x.mk

@@ -33,7 +33,6 @@ LIBC_X_A_DIRECTDEPS =				\
 	LIBC_RUNTIME				\
 	LIBC_STDIO				\
 	LIBC_STR				\
-	LIBC_STUBS				\
 	LIBC_SYSV				\
 	THIRD_PARTY_GDTOA			\
 	THIRD_PARTY_ZLIB

libc/x/xasprintf.c

@@ -24,11 +24,11 @@
  * @return must be free()'d or gc()'d
  * @note greatest of all C functions
  */
-char *(xasprintf)(const char *fmt, ...) {
+char *xasprintf(const char *fmt, ...) {
   char *res;
   va_list va;
   va_start(va, fmt);
-  res = (xvasprintf)(fmt, va);
+  res = xvasprintf(fmt, va);
   va_end(va);
   return res;
 }

libc/x/xvasprintf.c

@@ -16,7 +16,7 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/mem/fmt.h"
+#include "libc/stdio/stdio.h"
 #include "libc/x/x.h"
 #include "libc/x/xasprintf.h"
 
@@ -26,8 +26,8 @@
  * @return fully formatted string, which must be free()'d
  * @see xasprintf()
  */
-char *(xvasprintf)(const char *fmt, va_list va) {
+char *xvasprintf(const char *fmt, va_list va) {
   char *buf;
-  if ((vasprintf)(&buf, fmt, va) == -1) xdie();
+  if (vasprintf(&buf, fmt, va) == -1) xdie();
   return buf;
 }