MSVC: Recognize -XYZ as well as /XYZ when parsing MS tool command lines
A new version of !7510 (closed) , attempting to resolve all feedback while fixing #23772 (closed) . Note that in response to @fredrikclaesson 's comment, I've adopted the policy of not changing '-' to '/'. Also note that this replaces !7518 (closed) , which got rejected by @kwrobot because my commit message was too long.
Fixes: #23772 (closed)
Topic-rename: ms-tool-dash-flags
Edited by Brad King