This CL adds fuzzers for the wasm module sections 'types', 'names',
'globals', 'imports', 'function signatures', 'memory', and 'data', one
fuzzer per section. No fuzzers are added for the other sections because
either there already exists a fuzzer (e.g. wasm-code), or there exist
inter-section dependencies.

To avoid introducing a bunch executables which would make compilation
with make slow, I introduce a single executable
'v8_simple_wasm_section_fuzzer' which calls the fuzzers mentioned above.
This executable is run by the trybots and ensures that the fuzzers
actually compile. For debugging I introduce commandline parameters which
allow to execute the specific fuzzers from 'v8_simple_wasm_section_fuzzer'.

R=titzer@chromium.org, jochen@chromium.org, mstarzinger@chromium.org

Review-Url: https://codereview.chromium.org/2336603002
Cr-Commit-Position: refs/heads/master@{#39413}