[Swift CI] Build Failure: OSS - Swift Package - Ubuntu 18.04 (master) #2973

# [FAILURE] oss-swift-package-linux-ubuntu-18_04 [#2973]

Build URL: https://ci.swift.org/job/oss-swift-package-linux-ubuntu-18_04/2973/
Project: oss-swift-package-linux-ubuntu-18_04
Date of build: Sun, 07 Jun 2020 21:26:23 -0500
Build duration: 2 hr 20 min

Changes- Commit 71309a8fa95fe9f4c755804316bacb68fe0a2e5c by github:

Revert "[LTO] Support LLVM level link time optimization on Darwin, Linux

  • edit: include/swift/AST/IRGenOptions.h
  • edit: lib/Driver/ToolChains.h
  • delete: test/Driver/Inputs/lto/main.swift
  • delete: test/Driver/link-time-opt-lib.swift
  • edit: lib/Driver/DarwinToolChains.cpp
  • delete: test/Driver/link-time-opt-staticlib-thin.swift
  • delete: test/Driver/link-time-opt-lib-thin.swift
  • delete: test/Driver/Inputs/lto/lib.swift
  • delete: test/Driver/Inputs/lto/multifiles/main.swift
  • edit: utils/build-windows.bat
  • delete: test/Driver/Inputs/lto/multifiles/file.swift
  • delete: test/Driver/link-time-opt.swift
  • edit: include/swift/Driver/Driver.h
  • edit: include/swift/Driver/Action.h
  • edit: lib/Frontend/CompilerInvocation.cpp
  • edit: lib/IRGen/IRGenModule.cpp
  • delete: test/Driver/link-time-opt-staticlib.swift
  • edit: lib/Driver/WindowsToolChains.cpp
  • edit: lib/Driver/ToolChains.cpp
  • edit: lib/IRGen/IRGen.cpp
  • edit: lib/Driver/UnixToolChains.cpp
  • edit: include/swift/Option/Options.td
  • edit: lib/Driver/Driver.cpp