[TSan] Use zeroext for function parameters

SystemZ ABI requires zero-extending function parameters to 64-bit. The
compiler is free to optimize the code around this assumption, e.g.
failing to zero-extend __tsan_atomic32_load()'s morder may cause
crashes in to_mo() switch table lookup.

Fix by adding zeroext attributes to TSan's FunctionCallees, similar to
how it was done in commit 3bc439bd ("[MSan] Add instrumentation for
SystemZ"). This is a no-op on arches that don't need it.

Reviewed By: dvyukov

Differential Revision: https://reviews.llvm.org/D105629