Updates our Github Actions runners to install clang-format-21. Updates
runsuite.cmake to prefer that version.
Reformats our files with this version.
Fixes#8008
Updates all the "FIXME" comments in the repository to instead use "TODO"
(for those about missing implementations: "NYI" or
"ASSERT_NOT_IMPLEMENTED") or "XXX" (everything else). This matches our
style guide which discourages "FIXME" as its connotations are too
negative and too easily mis-interpreted by readers and in code audits to
imply that the current state of things is broken in some way instead of
just meaning something could be improved.
Adds load-acquire semantics to a number of bare loads (i.e., not
inside a mutex) in DR's various lock routines.
This includes a key missing load-acquire in the spinlock loop in
d_r_mutex_lock_app() which might help explain some performance issues
such as #4279.
Since some of these are in the utils.h header, and we have ordering
dependencies between utils.h and arch_exports.h, this required
splitting the atomic defines out of arch/arch_exports.h into a new
file arch/atomic_exports.h. Since those atomic defines use ASSERT
which references dynamo_options, this further required splitting the
option struct out of options.h into options_struct.h.
Issue: #2502, #4928, #4279
Derek Bruening