Remove ArrayData::nvSet() wrappers and several dead Array helpers.

nvSet() only casts the value from TypedValue* to const Variant&; do it
at callsites.  Inlined array_setm_ik1_v0() and array_setm_s0k1_v0() into
their only remaining callsites in translator-runtime.cpp.
Remove m_obj from c_Continuation

m_obj in c_Continuation is redundant. It is only used at the time
Continuation is created. First, it is set in init() call. Few
instructions later, it is read so that $this in the Continuation's
ActRec can be populated.

Kill it.
Fix static variables in closure generators

Each closure instance carries its own set of static variables. Multiple
generators created using the same closure instance should share their
static variables.

This was not the case and static variables in closure generators behaved
like normal local variables. Let's fix it by referencing closure and
using its static locals.

Pointer to the closure is located in the local following original input
arguments. These are shifted by one, as Continuation occupies local 0.

This also frees 8 bytes from c_Continuation (or 16 if you count 16-byte
alignment).
Run repo-authoritative tests in repo-authoritative mode

Because its the right thing to do. Even if some tests fail.
Fix an assembler bug with FPI region offsets

The assembler recorded the offset to FPI regions based on the
stack depth before the instruction executed.  This is trivially wrong
for instructions like FPushCtorD, but also breaks in nested FPI
regions.  The assembler is tracking fdescDepth independently of the
eval stack, so as long as we continue to require that all FPush* ops
logically push the ActRec *after* all their other pops and pushes,
this fix should work.  It might be nice to some day reword the
bytecode.specification stuff to include ActRecs as part of the eval
stack, though, so it isn't ambigious which order they happen for the
FPIEnt offsets.
Make stack walking logic from Stack::toString reusable

I need to walk a live eval stack, handling FPI regions and
generators, and duplicating that logic in yet another place seems
wrong.  This makes the Stack::toString stuff use a reusable one---at
some point I'll see if the unwinder can use it as well, but it works
also for my use case.  Also, Stack::toString was broken for mutable
array iterators---fixes that.  And use a union now for struct Iter.
And don't include bytecode.h from func.h.
Initial API for region selectors

Contains some structures to use for communicating between
compilation region selectors and the JIT.  For now includes two
debugging-oriented region selectors, one that uses a single HHBC
opcode at a time, and one that blindly pushes in the whole CFG for a
method using the Verifier::GraphBuilder.
clean up tests dir

I think this dir shouldn't have anything non-necessary in the root.