math package floating point exceptions

[James Walker <jamesw@...>]

When Lua is used on Windows, floating point exceptions can crash the 
host application.  I suggest adding some error checks, something like this:

static int math_asin (lua_State *L) {
  lua_Number arg = luaL_checknumber(L, 1);
  if (fabs(arg) > 1.0)
  	return luaL_error( L, "Illegal argument %f to math.asin", arg );
  lua_pushnumber(L, asin(arg));
  return 1;
}

Similar checks could also be added to acos, sqrt, pow, log, log10.

(I just joined the list, but first I searched the archive, and could not 
find anything about this.)
--
  James W. Walker, Innoventive Software LLC
  <http://www.frameforge3d.com/>