Fix test failures in XML::LibXML with libxml2-2.13

[Douglas R. Reno]

As reported by Drugo on blfs-dev, the test suite for XML::LibXML is broken with version 2.13 of libxml2. This can cause issues when using CPAN to install the module.

The fix is here: ​https://github.com/shlomif/perl-XML-LibXML/pull/87, and it has been picked up by NixOS.

[Douglas R. Reno]

Here's the current test summary report from this module:

Test Summary Report
-------------------
t/02parse.t                                      (Wstat: 256 (exited 1) Tests: 533 Failed: 1)
  Failed test:  511
  Non-zero exit status: 1
t/08findnodes.t                                  (Wstat: 256 (exited 1) Tests: 45 Failed: 1)
  Failed test:  14
  Non-zero exit status: 1
t/19die_on_invalid_utf8_rt_58848.t               (Wstat: 256 (exited 1) Tests: 1 Failed: 1)
  Failed test:  1
  Non-zero exit status: 1
t/60error_prev_chain.t                           (Wstat: 65280 (exited 255) Tests: 0 Failed: 0)
  Non-zero exit status: 255
  Parse errors: Bad plan.  You planned 1 tests but ran 0.
Files=77, Tests=2546,  6 wallclock secs ( 0.23 usr  0.03 sys +  5.09 cusr  0.57 csys =  5.92 CPU)
Result: FAIL
Failed 4/77 test programs. 3/2546 subtests failed.

[Douglas R. Reno]

With the patch applied I now get:

All tests successful.
Files=77, Tests=2548,  6 wallclock secs ( 0.22 usr  0.05 sys +  5.07 cusr  0.55 csys =  5.89 CPU)
Result: PASS

[Douglas R. Reno]

Fixed at cddf294649942a3d012d2f7be74edbd2aba2baf3