Shut up jobserver warning

Summary: Yes, seriously, this is the fix. I'm going to go cry in a
corner now. I'm just so far past rage for the creators of `make` and
`cmake`.

somuchrage

Reviewed By: @JoelMarcey

Differential Revision: D1401502
Fix a JIT crash in unsupported NewElem dims

Summary: I got a sandbox crash in ExternalThreadEventWaitHandle---the strangest
part is that it seemed to be trying to abandon a wait handle from the minstr
translator at JIT time.  Apparently in an opt build if we get an MW that we
don't understand we load a function to call out of these tables with an invalid
index and somehow we called some random code (I'm not 100% sure I understand
how).  The inspecting the junk in the crash led me to trying an FPassM with an
MW.  Just PUNT instead of crashing.

Reviewed By: @swtaarrs

Differential Revision: D1400770
deal with BSD stty output

Summary: I'm going to be working on a plane, so I'm getting it compiled on my laptop. The test runner doesn't love BSD.

Reviewed By: @JoelMarcey

Differential Revision: D1399789
Re-record assetic

Reviewed By: @fredemmott

Differential Revision: D1402727
Serialize Makefile build

Summary: @JoelMarcey is running into some weird issues after D1401502 allowed
this to be parallelized when called from cmake. I really really don't
care to debug it, and parallelization doesn't lose us that much, so just
serialize it.

Reviewed By: @JoelMarcey

Differential Revision: D1402916
Reorganize class.h

Summary: Ain't she a beaut'?  Organize and document all of class.h, and spawn off
a class-inl.h.

I'll organize class.cpp also, shortly before I start working on
rejiggering the loader logic.  This may not happen immediately, but this
cleanup is still good now.

Reviewed By: @jdelong

Differential Revision: D1399915