Summary:
Fix read/write in binary format, which crashes Python 3.
Additionally, clean up redundant (as for Python 3) code and
fix a handful of flake8 warnings.
Differential Revision: https://reviews.llvm.org/D79932
Using from __future__ import print_function it is possible to have a compatible behavior of `print(...)` across Python version.
Differential Revision: https://reviews.llvm.org/D55213
llvm-svn: 349454
Storing diffs.txt is now redundant, as we simply dump the CmpRuns output
to stdout (it is saved in CI and tends to be small).
Not generating those files enables us to remove empty folders, which
confuse git, as it would not add them with reference results.
llvm-svn: 316948