test: off JIT for routines in <lang/stackov.lua>

This patch is a follow-up to the commit
6a3a97c ("test: enable
<misc/stackovc.lua> LuaJIT test"). The enabled test may raise an error
for the specific builds (see [1], for example) when the stack overflow
error is raised on the trace exit during the restoration from the
snapshot. In that case, LuaJIT VM can't restore the full traceback, and
the corresponding check in the test is failed.

This patch disables JIT for these functions with recursive calls to
avoid such failures.

[1]: https://github.com/tarantool/luajit/actions/runs/10717386746

Follows up #9398

test/LuaJIT-tests/lang/stackov.lua

@@ -1,18 +1,22 @@
 local function f()
   f()
 end
+jit.off(f)
 
 local function g(i)
   g(i)
 end
+jit.off(g)
 
 local function vtail(...)
   return vtail(1, ...)
 end
+jit.off(vtail)
 
 local function vcall(...)
   vcall(1, ...)
 end
+jit.off(vcall)
 
 local function test_error_msg(func, s)
   local first = string.match(s, "[^\n]+")