Add exchange functions to alias the poorly named set functions.
Add store without reading previous. Faster on non-x86 processors.
Add compare-exchange that updates previous to avoid redundant fetch.
On Windows, load bool without conversion from char.
On Windows, load using mov with compiler barrier. Still seq_cst.
On POSIX, use GCC __atomic builtins.
Code submissions have continually suffered from formatting
inconsistencies that constantly have to be addressed. Using
clang-format simplifies this by making code formatting more consistent,
and allows automation of the code formatting so that maintainers can
focus more on the code itself instead of code formatting.
