Flags --dump_wasm_module and --dump_wasm_module_path=/path/to/folder allow us to run a bunch of tests and capture all of the wasm module files including the ones that come from the .js and .cc tests which are built on the fly, as well as the asm2wasm tests.

The files are all uniquely named `HASH.{ok,failed}.wasm`.

This will be especilly useful for fuzz testing, but could also be used for other tests including non-V8 tests.

For now I manually hacked tools/testrunner/local/execution.py so that tools/run-tests.py can output the modules. We may want to ad a flag to run-tests.py proper if this turns out to be useful.

R=bradnelson@chromium.org, titzer@chromium.org, kcc@chromium.org

Review URL: https://codereview.chromium.org/1816583003

Cr-Commit-Position: refs/heads/master@{#34968}