Merge "Update test for more accurate memtag_handle_longjmp" into main am: c923ea5a

}

__attribute__((noinline)) void mte_illegal_setjmp_helper(jmp_buf& jump_buf) {

  // Because the detection of illegal setjmp is done relative to the SP in setjmp,

  // we need to make sure this stack frame is bigger than the one of setjmp.

  // TODO(fmayer): fix that bug and remove the workaround.

  volatile char buf[1024];

  buf[0] = '1';

  // This frame is at least 8 bytes for storing and restoring the LR before the

  // setjmp below. So this can never get an empty stack frame, even if we omit

  // the frame pointer. So, the SP of this is always less (numerically) than the

  // calling function frame.

  setjmp(jump_buf);

}