[Perl/perl5] c18a27: add tests for U8TO64_LE() - work in progress

[Yves Orton]

  Branch: refs/heads/dmq/test_hv_macro
  Home:   https://github.com/Perl/perl5
  Commit: c18a27f3f916165eb32bf63e844788b3edbe1edf
      
https://github.com/Perl/perl5/commit/c18a27f3f916165eb32bf63e844788b3edbe1edf
  Author: Yves Orton <demer...@gmail.com>
  Date:   2019-11-06 (Wed, 06 Nov 2019)

  Changed paths:
    M MANIFEST
    M ext/XS-APItest/APItest.xs
    A ext/XS-APItest/t/hv_macro.t

  Log Message:
  -----------
  add tests for U8TO64_LE() - work in progress