Revert of added support for push_constant layout (patchset #7 id:140001 of https://codereview.chromium.org/2187433003/ )

Reason for revert:
hitting assert in vulkan

Original issue's description:
> added support for push_constant layout
>
> BUG=skia:
> GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2187433003
>
> Committed: https://skia.googlesource.com/skia/+/fa5f65ac61fd525029aa9dab161ffe4896c10f6d

TBR=ethannicholas@google.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review-Url: https://codereview.chromium.org/2509673002
13 files changed