tree cde573a34f3a229056e84b637a67aecc75b91ed1
parent c545d6f10fa4827de235b5f85b58e803eba725bc
author David Gross <dgross@google.com> 1455832832 -0800
committer David Gross <dgross@google.com> 1455926599 -0800

Metadata extractor must tolerate missing accumulator function.

Looking up a general reduction accumulator function by name can fail,
just as looking up a foreach kernel function by name can fail: One of
the uses of MetadataExtractor is as part of the RSEmbedInfoPass, which
bcc_compat runs sufficiently late in the phase order that
RSKernelExpandPass has already run and the original (UNexpanded)
accumulator function may have been deleted as having no references (if
it has been inlined into the expanded accumulator function and is
otherwise unreferenced).

Bug: 23535724
(cherry picked from commit 34383a2fcec623b8696308d36e9522afb0c5b23d)

Change-Id: If9eba2bfca4c591de7bd5a464cf76e45007b3295