Reland "[clang-scan-deps] Add support for clang-cl"

This reverts commit 199c3974.
This time, clang-scan-deps's search for output argument in clang-cl command line will now ignore arguments preceded by "-Xclang".
That way, it won't detect a /o argument in "-Xclang -ivfsoverlay -Xclang /opt/subpath"

Initial patch description:
clang-scan-deps contains some command line parsing and modifications.
This patch adds support for clang-cl command options.

Differential Revision: https://reviews.llvm.org/D92191