* Port Microsoft-internal MSVC-PR-218746 and MSVC-PR-219383.
* And MSVC-PR-219451:
* Skip llvm-project in validate.cpp.
* Change .vscode/settings.json to CRLF.
This file is gitignored, so it will provide default settings that can
be further customized without showing up as pending changes.
It enables `editor.formatOnSave` to help with clang-format enforcement.
It sets `files.eol` to CRLF and enables `files.insertFinalNewline`,
`files.trimFinalNewlines`, and `files.trimTrailingWhitespace` to help
with whitespace enforcement.
It uses `files.associations` to mark our extensionless headers as C++.
It excludes the `stl/msbuild` subdirectory (which isn't used by the
GitHub repo, and is doomed soon). It also excludes the `vcpkg`
submodule, to prevent its files from showing up in Quick Open (Ctrl+P).
Stephan T. Lavavej