Make generated code match a style guide

[mithro]

It would be good if the generated code matched an existing style guide. I have a lot of experience with the Google C++ style guide @ https://google.github.io/styleguide/cppguide.html As you are using exceptions which the Google C++ style guide forbids, maybe that isn't a good match.

Since this code is supposed to end up in VtR, generating something which matches the clang-format at https://github.com/SymbiFlow/vtr-verilog-to-routing/blob/master%2Bwip/.clang-format might be a good idea too.

[duck2]

I'm thinking about getting rid of the exceptions, since it's not clear what happens to the allocated memory so far after parsing fails.

For vpr, running make format after copying the generated files works OK. It would be even better to run clang-format only on the generated files.