This patch speculatively implements the PR for LWG 2937, which fixes
two issues with equivalent.
(1) It makes equivalent("dne", "exists") an error. Previously only
equivalent("dne", "dne") was an error and the former case was not (it returned false).
Now equivalent reports an error when either input doesn't exist.
(2) It makes equivalent(p1, p2) well-formed when `is_other(p1) && is_other(p2)`.
Previously this was an error, but there is seemingly no reason why it should be on POSIX system.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@307117 91177308-0d34-0410-b5e6-96231b3b80d8
Add the completed std::experimental::filesystem implementation and tests.
The implementation supports C++11 or newer.
The TS is built as part of 'libc++experimental.a'. Users of the TS need to
manually link this library. Building and testing the TS can be disabled using
the CMake option '-DLIBCXX_ENABLE_FILESYSTEM=OFF'.
Currently 'libc++experimental.a' is not installed by default. To turn on the
installation of the library use '-DLIBCXX_INSTALL_EXPERIMENTAL_LIBRARY=ON'.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@273034 91177308-0d34-0410-b5e6-96231b3b80d8
