[LLVM] [Support] Disable ioctl() terminal size check on Solaris (#144600)

#143514 broke the `clang-solaris11-sparcv9` bot; from what I can tell
that’s Solaris and according to `SolarisTargetInfo::getOSDefines`, the
macro `__sun__` should be defined on Solaris, so check for that and
don’t try to query the terminal size if it is defined.

Not sure this is the best solution but hopefully it fixes the bot.

Author: Sirraide

llvm/lib/Support/Unix/Process.inc

@@ -320,7 +320,7 @@ static unsigned getColumns(int FileID) {
   // instead if it isn't available.
   unsigned Columns = 0;
 
-#ifdef HAVE_SYS_IOCTL_H
+#if defined(HAVE_SYS_IOCTL_H) && !defined(__sun__)
   struct winsize ws;
   if (ioctl(FileID, TIOCGWINSZ, &ws) == 0)
     Columns = ws.ws_col;