[all-commits] [llvm/llvm-project] 0e8eb4: [libc] Fix read under msan (#80203)

[michaelrj-google via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 0e8eb445db0cc2552d9d077b527a43c779785cb9
      https://github.com/llvm/llvm-project/commit/0e8eb445db0cc2552d9d077b527a43c779785cb9
  Author: michaelrj-google <71531609+michaelrj-google at users.noreply.github.com>
  Date:   2024-01-31 (Wed, 31 Jan 2024)

  Changed paths:
    M libc/src/unistd/linux/read.cpp
    M utils/bazel/llvm-project-overlay/libc/BUILD.bazel

  Log Message:
  -----------
  [libc] Fix read under msan (#80203)

The read function wasn't properly unpoisoning its result under msan,
causing test failures downstream when I tried to roll it out. This patch
adds the msan unpoison call that fixes the issue.