Avoid using lightuserdata in internal wrapper code for the math module.

src/modules/math/wrap_Math.cpp

@@ -500,7 +500,7 @@ extern "C" int luaopen_love_math(lua_State *L)
 	// Execute wrap_Math.lua, sending the math table and ffifuncs pointer as args.
 	luaL_loadbuffer(L, math_lua, sizeof(math_lua), "wrap_Math.lua");
 	lua_pushvalue(L, -2);
-	lua_pushlightuserdata(L, &ffifuncs);
+	luax_pushpointerasstring(L, &ffifuncs);
 	lua_call(L, 2, 0);
 
 	return n;

src/modules/math/wrap_Math.lua

@@ -22,7 +22,7 @@ misrepresented as being the original software.
 3. This notice may not be removed or altered from any source distribution.
 --]]
 
-local love_math, ffifuncspointer = ...
+local love_math, ffifuncspointer_str = ...
 
 local type, tonumber, error = type, tonumber, error
 local floor = math.floor
@@ -103,7 +103,7 @@ typedef struct FFI_Math
 } FFI_Math;
 ]])
 
-local ffifuncs = ffi.cast("FFI_Math *", ffifuncspointer)
+local ffifuncs = ffi.cast("FFI_Math **", ffifuncspointer_str)[0]
 
 
 -- Overwrite some regular love.math functions with FFI implementations.