Revert "[fuzzer][Fuchsia] Prevent deadlock from suspending threads" (#155042)

Reverts llvm/llvm-project#154854 because it broke Clang toolchain
builders for Fuchsia:

https://luci-milo.appspot.com/ui/p/fuchsia/builders/toolchain.ci/clang-linux-x64/b8705803649235662417/overview

NOKEYCHECK=True
GitOrigin-RevId: 781a4db6b50bb660cb293d3e7e29957aeb4b02ac
2 files changed