To remove JSRESOLVE_ASSIGNING, we need to remove all things that depend on it. |bool set| arguments often do -- but it's hard to grep for tests of them. Changing to |unsigned flags| arguments, and making all tests use JSRESOLVE_ASSIGNING, makes pellucid all proxy set-dependent behavior. Note that bholley wanted me to maintain this patch locally and not land it, but the size and scope of this thing makes me think that's really not a good idea. Plus, it's really handy to be able to depend on MXR when surveying the remaining uses of JSRESOLVE_ASSIGNING, which means getting this landed. This is somewhat mechanical/straightforward, but I'll do a try run before landing to be safe. :-)

I also added a few MOZ_OVERRIDEs in places where it made sense, since I was already changing overriding methods and it was pretty obvious where it could be used.

Comment on attachment 697632 [details] [diff] [review] Guh, qref Why does the Value* version of get(Own)PropertyDescriptor not change arg order? r=me modulo that.

https://tbpl.mozilla.org/?tree=Try&rev=b7c8ff502214 checked out, so pushed: https://hg.mozilla.org/integration/mozilla-inbound/rev/79b2064c1a99