If the command line option contains /DEBUG without the following
argument, GenerateDebugInformation remained 'false' because the
DebugInfoOption contained the initial value.
Set GenerateDebugInformation to 'true' if the /DEBUG option is found and
reset to 'false' only if option is set to 'none'.
Amends commit 6a6b27940d.
Pick-to: 6.2 6.4 6.5 5.15
Fixes: QTBUG-110068
Change-Id: I792d7335d8b9536d4beed54cabfd70dcf54f09ac
Reviewed-by: Alexey Edelev <alexey.edelev@qt.io>
Reviewed-by: Jörg Bornemann <joerg.bornemann@qt.io>