Different formatting styles on the generated test/format/format_config_def.c lead to lots of hard-to-read diffs in branch changes and pull requests.  If we standardize them, we can eliminate the distracting differences.

For example, person A makes a change to config.sh, runs the script and checks in the change.  Person B makes a change to config.sh, runs the script, then explicitly runs {{s_clang_format test/format/format_config_def.c }}and gets a differently formatted version.  Person C makes a change to config.sh, runs the script, then visits the generated file in their smart editor that formats and autosaves.

These are all valid workflows, but leads to churn in the file and diffs.

Note that s_clang_format when run with no arguments or -F, will not reformat this file, it's on an exception list.  So no formatting is enforced.   Past history of this file (which has changed names a couple times) shows lots of spurious churn.

We propose to standardize formatting by 1) having config.sh run clang_format as a final step 2) remove format_config_def.c as an exception.