Juggle around where a pointer comes from to ensure that it passes MIRI
cleanly.

)

This commit fixes a bug in initializing memory segments of 32-bit
memories where if the offset was negative when viewed as a signed
integer the offset was incorrectly sign-extended to a 64-bit value
instead of zero-extended. This commit replaces an `i32`-to-`u64` cast
with an `i32`-to-`u32` cast followed by a `u32`-to-`u64` cast which
performs the zero extend.

Closes bytecodealliance#7558

…tecodealliance#7561)

* Configure Rust lints at the workspace level

This commit adds necessary configuration knobs to have lints configured
at the workspace level in Wasmtime rather than the crate level. This
uses a feature of Cargo first released with 1.74.0 (last week) of the
`[workspace.lints]` table. This should help create a more consistent set
of lints applied across all crates in our workspace in addition to
possibly running select clippy lints on CI as well.

* Move `unused_extern_crates` to the workspace level

This commit configures a `deny` lint level for the
`unused_extern_crates` lint to the workspace level rather than the
previous configuration at the individual crate level.

* Move `trivial_numeric_casts` to workspace level

* Change workspace lint levels to `warn`

CI will ensure that these don't get checked into the codebase and
otherwise provide fewer speed bumps for in-process development.

* Move `unstable_features` lint to workspace level

* Move `unused_import_braces` lint to workspace level

* Start running Clippy on CI

This commit configures our CI to run `cargo clippy --workspace` for all
merged PRs. Historically this hasn't been all the feasible due to the
amount of configuration required to control the number of warnings on
CI, but with Cargo's new `[lint]` table it's possible to have a
one-liner to silence all lints from Clippy by default. This commit by
default sets the `all` lint in Clippy to `allow` to by-default disable
warnings from Clippy. The goal of this PR is to enable selective access
to Clippy lints for Wasmtime on CI.

* Selectively enable `clippy::cast_sign_loss`

This would have fixed bytecodealliance#7558 so try to head off future issues with that
by warning against this situation in a few crates. This lint is still
quite noisy though for Cranelift for example so it's not worthwhile at
this time to enable it for the whole workspace.

* Fix CI error

prtest:full

Signed-off-by: Tyler Rockwood <rockwood@redpanda.com>

…st (bytecodealliance#7564)

* move wasmtime-wasi's unit test for stdin to a separate integration test

fork is always a terrible idea, but when we wrote this test, we couldn't
think of an alternative method. alex showed us how
`/tests/host_segfault.rs` works, which solves a similar problem for
measuring process behavior without forking.

the forking version of this test would occasionally hang in the child's
creation of a tokio runtime because std Once is not fork-safe (nor
should it be. nothing should be fork-safe. forks are an abomination).

so instead, this is now a separate integration test with `harness =
false` that will exec itself in order to run the child.

* wasmtime-wasi: add tests to package include