glibc patch: add backwards compatibility for some symbols

- `fcntl` was renamed to `fcntl64` in glibc 2.28 (see #9485)
- `res_{,n}{search,query,querydomain}` became "their own" symbols since
  glibc 2.34: they were prefixed with `__` before.

This PR makes it possible to use `fcntl` with glibc 2.27 or older and
the `res_*` functions with glibc 2.33 or older.

These patches will become redundant with universal-headers and can be
dropped. But we have to do with what we have now.

lib/libc/glibc/io/fcntl.h

@@ -167,6 +167,10 @@ typedef __pid_t pid_t;
 					   effective IDs, not real IDs.  */
 #endif
 
+
+/* fcntl was a simple symbol until glibc 2.27 inclusive. glibc 2.28 onwards
+ * re-defines it to fcntl64 (via #define) if _FILE_OFFSET_BITS == 64. */
+#if (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 28) || __GLIBC__ > 2
 /* Do the file control operation described by CMD on FD.
    The remaining arguments are interpreted depending on CMD.
 
@@ -197,6 +201,9 @@ extern int __fcntl_time64 (int __fd, int __request, ...) __THROW;
 #  define fcntl __fcntl_time64
 # endif
 #endif
+#else /* glibc 2.27 or lower */
+extern int fcntl (int __fd, int __cmd, ...);
+#endif
 
 /* Open FILE and return a new file descriptor for it, or -1 on error.
    OFLAG determines the type of access used.  If O_CREAT or O_TMPFILE is set