Disable CommandLineToArgvW-standard quoting for cmd.exe.
libuv assumes spawned processes follow the convention expected by
CommandLineToArgvW(). But cmd.exe is non-conformant, so for cmd.exe:
- With system([]), the caller has full control (and responsibility) to
quote arguments correctly.
- With system(''), shell* options are used.
libuv quoting is disabled if argv[0] is:
- cmd.exe
- cmd
- $COMSPEC resolving to a path with filename cmd.exe
Closes#6329
References #6387
f3cc843755
