[Reg: 5.5.1->5.6] Problems with key shortcuts and key modifiers

Since https://codereview.qt-project.org/#/c/125142/ I've got problem with key modifiers (tested on Linux and Windows XP).

I attached test program. The key sequence which I test: "Shift+8", "Shift+8", "*" on numpad, "Shift+]"

Output from Qt 5.6 ("Shift+]" doesn't work), as in Qt 5.5.0:
QKeySequence("Shift+*")
QKeySequence("Shift+*")
QKeySequence("*")

Output from Qt 5.5.1, as in Qt 4.8:
QAction::eventFilter: Ambiguous shortcut overload: *
QAction::eventFilter: Ambiguous shortcut overload: Shift+8
QKeySequence("*")
QKeySequence("Shift+]")

"Ambiguous", because "Shift+8" and "*" are exactly the same.

It also has a bug with modal dialog (5.6 beta and 5.5.0, also included in test program, worked properly on Qt 5.5.1 and Qt 4.x and 5.6 before https://codereview.qt-project.org/#/c/125142/):

• select first row on the list,
• open modal dialog by key shortcut "Shift+S",
• close modal dialog by keyboard (Esc or Return),
• notice that list gets "s" key and it selects another item which contains "s" in name.