[TSan] Fix atomicrmw xchg with pointer and floats (#85228)

atomicrmw xchg also accepts pointer and floating-point values. To handle
those, insert necessary casts to and from integer. This is what we do
for cmpxchg as well.

Fixes https://github.com/llvm/llvm-project/issues/85226.

(cherry picked from commit ff2fb2a1)