Revert r342637 "[ADT] Try again to use the same version of llvm::Optional on all compilers"

and also revert follow-ups r342643 and r342723.

This caused Clang to be miscompiled by GCC 4.8.4 (Unbuntu 14.04's
default compiler) and break the Chromium build (see
https://crbug.com/888061).

llvm-svn: 342966
1 file changed
tree: 403d638c73dba44da28fc4fbb5fd600cd5b793c7
  1. clang/
  2. clang-tools-extra/
  3. compiler-rt/
  4. debuginfo-tests/
  5. libclc/
  6. libcxx/
  7. libcxxabi/
  8. libunwind/
  9. lld/
  10. lldb/
  11. llgo/
  12. llvm/
  13. openmp/
  14. parallel-libs/
  15. polly/
  16. README.md
README.md

Low Level Virtual Machine (LLVM)

This directory and its subdirectories contain source code for LLVM, a toolkit for the construction of highly optimized compilers, optimizers, and runtime environments.