.clang_format is at the top of repository, but it seems the code was not formatted by clang-format

I am running clang-format on src/cc/bcc_exception.h:
```
$ clang-format -i src/cc/bcc_exception.h
```
The entire file pretty much was all edited.

So if I update .clang-format to match the existing style (for example, pointer affix to variable instead of type char *ptr vs. char* ptr), would it make sense to ask contributter to run clang-format before sending PR, and add clang-format checker somewhere in the PR process?

Compare the existing style in src/cc/bcc_exception.h with the repository's .clang-format configuration, starting with the pointer-affix example in the issue. Review the current pull-request process to determine where formatting validation could run. Done means the agreed style is represented by the configuration and formatting is checked during pull requests.

Written by the indexing model from the issue text.