codeGen/tsan: Disable instrumentation of unaligned stores
There is some disagreement regarding the prototype of
__tsan_unaligned_write
(specifically whether it takes just the written
address, or the address and the value as an argument). Moreover, I have
observed crashes which appear to be due to it. Disable instrumentation
of unaligned stores as a temporary mitigation.
Fixes #23096 (closed).