Both these files are provided in the distributed tarball for 3.3.0-rc2. I suggesttaking care of removing them, and probably add something in the build system so that they're cleaned when running "make distclean"
You are right.
I changed the 'make clean' in the build-docs script to 'make distclean' (162e4b66 in v3-3-test). That fixes the issue.
Thanks for reporting!