This adds a start method to the Context to make starting a command less
tedious and yield consistent errors.
Manually setting the memory is still valid for more complex scenarios,
just undocumented for the time being.
This brings in revised tests for clock_time_get from upstream and
re-enables them.
This revision of these tests allow for lower precision clocks (we only
provide millisecond precision, and that is conformant but previous
tests for this in the upstream test suite were a bit more aggressive).
This fast-forwards wasi-test-suite a couple of commits removed
duplicate, or near duplicate tests with not much additional value.
Other tests have been merged to reduce the number of modules to make
tests topical to the syscall that is being tested.
This explicitly lists std/wasi test modules in a pre-sorted array for deterministic test runs.
As a side effect it makes it a bit more visible when a test has been added or removed aside
from having to look at the submodule update.
This commit renames Module and ModuleOptions to context to avoid stutter
confusion, e.g avoid having documentation that says things like
instantiate the snapshot's module's module.
