supported on x86/x86-64 and PowerPC. It is performed if:</p>
<ul>
- <li>Caller and callee have the calling convention <tt>fastcc</tt>.</li>
+ <li>Caller and callee have the calling convention <tt>fastcc</tt> or
+ <tt>cc 10</tt> (GHC call convention).</li>
<li>The call is a tail call - in tail position (ret immediately follows call
and ret uses value of call or is void).</li>