The test Run_Wasm_StoreMem_offset_oob contained an I64STORE instruction,
which is not yet implemented on 32 bit platforms. I turned off those
parts of the test on 32 bit platforms which contain I64 instructions.

R=bradnelson@chromium.org

Review URL: https://codereview.chromium.org/1526573002

Cr-Commit-Position: refs/heads/master@{#32842}