Add support for ewasm evmc vm.

[aarlt]

Closes #8016.

Replaces #9057.

This PR enables the possibility to run tests against ewasm evmc vms.

In contrast to #9057, where n-evmc vms could be defined, this PR is more simple. It enables the definition of up-to two different evmc libaries. To execute the tests, at least one evm1 vm must be defined (either through the --evmonepath parameter, or with --vm), where the defintion of an ewasm vm is optional. If an ewasm evmc library was defined (via --vm), tests will also run against that ewasm evmc vm.

• Basic structure
• SemanticTest: add support for compileToEwasm
• Basic CircleCI integration to also run Semantic Tests via ewasm vm (moved to [circleci] Add support for hera evmc vm. #9212)

[axic]

@aarlt we are working on landing ewasm/hera#554. It will be released as Hera 0.3.0.

[axic]

@aarlt done, available here: https://github.com/ewasm/hera/releases/tag/v0.3.0

[aarlt]

Some test-cases seem to hang inside hera (e.g. nested_for_loop_multiple_local_vars). It looks like that this is mainly related to tests using loops that generate infinity loops. Right now metering is not enabled for the ewasm tests. I think some tests hang in hera because of not enabled metering and wrongly generated code leading to infinity loops.

[aarlt]

What is the status here?

@chriseth I think it's ready. I split out the CircleCI integration #9481 and currently trying to enable as much tests as possible while fixing some polyfills in #9508. From my point of view this PR #9143 and the CircleCI #9481 could get merged. All ewasm based tests are disabled in #9481 and #9143. Related tests get enabled in #9508.

One thing: I added in a new CircleCI job t_osx_test in #9481 that will also run soltest_all.sh in osx. If #9508 is passing the tests now, it would be nice to merge #9481 and #9143. And then we can fully focus on getting #9508 ready.

I removed now the t_osx_test CircleCI job. Maybe we should think about how to extent the bytecode comparision tests with ewasm.