Yesterday I setup a xenofarm client at devel2.cuci.nl. It compiles 8.0 and 8.1 using an identical set of configure parameters.
Yet, looking at the results, it appears that 8.1 comes out clean through the testsuite, yet 8.0 has six persistent testsuite failures.
I only get two errors. One is the certificate issue, where the test case isn't updated to reflect the less strict certificate handling in the X.509 module. These changes were introduced after the last release (and introduced to address real world compatibility issues with web servers sending harmless junk in their certificate chains)
The other issue is the no common suites error when testing TLS_rsa_with_null_sha256. I believe this is simply an error in the test suite and not the code, but it hasn't been high on the priority list, given that the suite in question isn't used anywhere besides for debugging purposes (and wasn't part of earlier releases, so not a regression).
The other errors you have are new to me, and all appears to have to do with serialization of Pike code (of which I know nothing).