commit 4cad76dcdf3d93de0d1787ff0cc51ce383700517
author Todd Wang <toddw@google.com> Sat Apr 09 10:58:12 2016 -0700
committer Todd Wang <toddw@google.com> Mon Apr 11 20:27:21 2016 +0000
tree 94dc9347049a8785ec595fd172bfe0e83b7d525e
parent a18b0088d835c82a71bff3884374d56970ab68c4

Fix some VDLRead bugs and minor clean-up.

While I was implementing the reflect version of VDLRead, I
noticed some bugs in both the vdl.Value and codegen versions of
VDLRead, so I fixed them.

The codegen set/map version was wrong because it was
early-existing when the lenhint is 0, rather than calling
NextEntry until it returned done.  The lenhint handling in
general was wrong for multiple types; we need to ensure we end up
with nil collections if there are no entries.

I also made the codegen version of array faster, by filling the
elem in directly, rather than using a temp variable.  I changed
the vdl.Value version list to add support for our eventual world
where the LenHint really isn't set, and employed a simple growth
strategy.

I also noticed that the type compatibility checks we added make
our benchmarks 20% worse.  We can deal with that later.

MultiPart: 3/4
Change-Id: Ice2c7e85edb8d7e555394008dcba857425dfb8b5