[WinEH] Fix catch block parent frame pointer offset
r367088 made it so that funclets store XMM registers into their local
frame instead of storing them to the parent frame. However, that change
forgot to update the parent frame pointer offset for catch blocks. This
change does that.
Fixes crashes when an exception is rethrown in a catch block that saves
XMMs, as described in https://crbug.com/992860.