Log Message:
Update to 1.28

Upstream changes:
1.28  2022-12-21  XMATH
    - Fix compatibliity with perl 5.37.3 and later
    - Fix support for state-variables (alias state $x = ...)
    - Fix handling of negative literal array index (alias $x[-1] = ...)

1.27  2022-12-02  XMATH
    - Fix tests on older perl versions

1.26  2022-12-01  XMATH
    - Fix compile error when using perl 5.37.2 or later
    - Improve diagnostic output from tests