Here is a simpler approach, if you can use Inline::C:

#!/usr/bin/perl -w
use strict;

use Inline C => q{ int evalseq() { return PL_evalseq; }};

for (1 .. 10) {
  eval q{ print "in eval (", evalseq(), ")\n" };
  print "outside eval (", evalseq(), ")\n";
}
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Of course this delves into undocumented internals, so no guarantee that it will work with every past and future version of perl. (It may also need a pTHX or something for threaded builds, but I don't have one handy to check.)

Hugo