This was completely broken -- we weren't walking down the type tree at
all.

Bug: b/124388146
Change-Id: I359d121403c3413e74427fadf57fd4c3d52f7661
Reviewed-on: https://swiftshader-review.googlesource.com/c/25088Tested-by: Chris Forbes <chrisforbes@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>