Revision of stackless implementation

- more organized handling of 'nCcalls'
- comments
- deprecation of 'setcstacklimit'

llimits.h

@@ -234,6 +234,17 @@ typedef l_uint32 Instruction;
 #endif
 
 
+/*
+** Maximum depth for nested C calls, syntactical nested non-terminals,
+** and other features implemented through recursion in C. (Value must
+** fit in a 16-bit unsigned integer. It must also be compatible with
+** the size of the C stack.)
+*/
+#if !defined(LUAI_MAXCCALLS)
+#define LUAI_MAXCCALLS		200
+#endif
+
+
 /*
 ** macros that are executed whenever program enters the Lua core
 ** ('lua_lock') and leaves the core ('lua_unlock')