Otherwise they come out in random (inode?) order.
Also `chmod +x` the generator, and re-run it. Somehow on Marek's
machine it produced \r\n line endings?! Open all files with
`newline='\n'` so that (if the Python3 docs are correct)
that won't happen again.
Differential Revision: https://reviews.llvm.org/D93137
Instead of having to remember the command-line to use every time, this
commit adds a CMake target to generate the ABI list in the current
configuration, if it is supported.
As a fly-by change, remove scripts that are now unused (sym_match.py
and sym_extract.py).