This header file is only used from tests.
Also, move the LoadStoreOpcodeOf method (only used in tests) from
wasm-opcodes.h to wasm-macro-gen.h.

R=ahaas@chromium.org

Change-Id: I8d4691be494b5c1fbe3084441329850930bad647
Reviewed-on: https://chromium-review.googlesource.com/486861
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44845}