Implement call hooks (zero-cost if disabled).

doc/changes.html

@@ -56,6 +56,8 @@ to see whether newer versions are available.
 <h2 id="snap">Development Snapshot</h2>
 <ul>
 <li>Build of preliminary x64 interpreter works on Linux/x64 or WIN64.</li>
+<li>Implement call hooks (zero-cost if disabled).</li>
+<li>Major redesign of internal function call handling.</li>
 <li>Implement yield from C hooks.</li>
 <li>Add abstract C call handling to IR.</li>
 <li>Improve KNUM fuse vs. load heuristics.</li>

doc/status.html

@@ -89,7 +89,7 @@ unexpected results — please report it. There are only very few
 known incompatibilities with standard Lua:
 <ul>
 <li>
-The Lua <b>debug API</b> is missing a couple of features (call/return
+The Lua <b>debug API</b> is missing a couple of features (return
 hooks) and shows slightly different behavior (no per-coroutine hooks,
 no tail call counting).
 </li>