Run the `clang-format.bash` script to update all our C and C++ code to a
new style defined by `.clang-format`. Use `clang-format` version 6.0.
* If you reached this commit for a line in `git blame`, re-run the blame
operation starting at the parent of this commit to see older history
for the content.
* See the parent commit for instructions to rebase a change across this
style transition commit.
Extend the write_compiler_detection_header interface to allow
specifying a location for supplementary files, and getting the
list of resulting files as a variable.
Provide a function to write a portable header to detect compiler
features. Generate a preprocessor #error for unknown compilers
and compiler versions whose features are not yet recorded. This
error condition might be relaxed in the future, but for now it
is useful for verification of expectations.
