eglibc-use-option-groups.patch removes some tests from tests-special to condition them on $(OPTION_POSIX_REGEXP_GLIBC), but when adding them back fails to include the .out suffix that is now present on the test names (all test output files having been renamed in glibc to have .out suffixes where they didn't already). This means test runs fall over in that directory because there are no rules to make the files $(objpfx)bug-regex14-mem $(objpfx)tst-rxspencer-no-utf8-mem $(objpfx)tst-pcre-mem $(objpfx)tst-boost-mem listed in tests-special after the patch, only the proper .out versions.
Posted patch for review to openembedded-core, see https://www.mail-archive.com/openembedded-core%40lists.openembedded.org/msg58903.html
Simple fix, adding the .out extension to the four offending test programs. Posted a patch for a review to openembedded-core https://www.mail-archive.com/openembedded-core%40lists.openembedded.org/msg58903.html
Merged, commit c453597d44a1a2301f4be7bf7a0853ea12eb448c