[wtp-releng] FYI: I've added JEM M2 to build

[David M Williams <david_williams@xxxxxxxxxx>]

This is our last "M5 pre-req"
and means our Wednesday builds will be near final for our M5. 

I've heard from one team that they plan
to release a few fixes on Wednesday, but after that (say, Wednesday at
5 PM eastern) 
I'll turn off the builds for M5 so we'll
have one full day (Thursday) to confirm and verify the M5 build to be declared
on Friday.