Data race in interfaces/libpq/fe-exec.c

This line
https://github.com/postgres/postgres/blob/30012a04a6c8127397a8ab71e160d9c7e7fbe874/src/interfaces/libpq/fe-exec.c#L1073
triggers data race errors when run under ThreadSanitizer (*)

As far as I can tell, the static variable in question is a hack to allow a
couple of deprecated functions that are already unsafe to use
(PQescapeString and PQescapeBytea) to be fractionally less unsafe to use.

Would there be any interest in a patch changing the type of
static_client_coding
and static_std_strings
<https://github.com/postgres/postgres/blob/30012a04a6c8127397a8ab71e160d9c7e7fbe874/src/interfaces/libpq/fe-exec.c#L49>
to
some atomic equivalent, so the data race goes away?

I know that as long as clients aren't daft enough to call PQescapeString or
PQescapeBytea, then the static variables are write-only - but wiser heads
than mine assure me that even if nothing ever reads from the variables,
unguarded simultaneous writes can cause issues when built with particularly
aggressive compilers... On the plus side: "As a note for changing the
variable to be atomic - if it uses acquire-release semantics, it'll be free
on x86 (barring any potential compiler optimisations that we *want* to
stop). And relaxed semantics should be free everywhere."

And it would be nice to be able to keep running my postgres-using tests
under ThreadSanitizer...

thanks

Mark

(*) specifically in a test that kicks off two simultaneous threads whose
first action is to open a postgres connection.