AltGr key and mintty

[Enrico Forestieri]

According to
https://github.com/mintty/mintty/wiki/Keycodes#altgr
when the keyboard layout does not have a keycode for an AltGr
combination, the AltGr key is treated as Alt instead.

I have the following entry in ~/.inputrc

"\e'": "`"			# Alt+' -> `

and, as AltGr+' is not a valid combination in my keyboard layout,
until mintty 3.1.6 by pressing it I was obtaining the wanted backtick
character. However, since mintty 3.1.7, this key combination now
produces nothing. One has to explicitly use LeftALt+' to obtain the
backtick. This is inconvenient because one needs to use both hands,
while AltGr+' can be easily triggered with a single hand.

-- 
Enrico