Log Message:
libuv: updated to 1.20.0

1.20.0:
* unix,spawn: respect user stdio flags for new pipe
* Revert "Revert "unix,tcp: avoid marking server sockets \ 
connected""
* req: revisions to uv_req_t handling
* win: remove unnecessary initialization
* win: update uv_os_homedir() to use uv_os_getenv()
* test: fix tcp_oob test flakiness
* posix: fix uv__pollfds_del() for invalidated fd's
* doc: README: add note on installing gyp
* unix: refactor uv_os_homedir to use uv_os_getenv
* unix: fix several instances of lost errno
* win,tty: update several TODO comments
* unix: add UV_FS_COPYFILE_FICLONE support
* test: fix connect_unspecified
* unix,win: add UV_FS_COPYFILE_FICLONE_FORCE support
* win: use long directory name for handle->dirw
* build: build with -D_FILE_OFFSET_BITS=64 again
* win, fs: fix uv_fs_unlink for +R -A files
* win, fs: use FILE_WRITE_ATTRIBUTES when opening files
* unix: use __PASE__ on IBM i platforms
* test,freebsd: fix flaky poll tests
* test: increase connection timeout to 1 second
* win,tcp: handle canceled connect with ECANCELED