* cannon: MIPS2 MT-FPVM contract

Add a smart contract implementing the multi-threaded Cannon

* Update packages/contracts-bedrock/src/cannon/libraries/MIPSSyscalls.sol
Co-authored-by: mbaxter <meredith@oplabs.co>

* cannon: Use common constant for BRK_START

* cannon: Define new constant FUTEX_EMPTY_ADDR

* cannon: Add SYS_ERROR_SIGNAL constant, fix futex wait ret val

* dedup syscall handling; rename timeout

* fix sys_clone bug

* use handler functions in onWaitComplete

* fix nits

* fix ETIMEDOUT constant

* remove leftover console import

* traverse right if left is empty on futex_wake syscall

* Update packages/contracts-bedrock/test/cannon/MIPS2.t.sol
Co-authored-by: mbaxter <meredith@oplabs.co>

* fix traverseRight updates at popThread

* exit syscall is exit_group if last thread

* simplify wakeup logic; traverse fully before any other operation

* remove dup logic for wakeup traversal end

* fuzz thread.exited in wakeup tests

* update semver-lock; abi snapshots

* implement unused syscalls

* rebase; fix clone args

* update semver-lock

* handle munmap

* add comment on unimplemented syscalls

* add mising snapshots

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Co-authored-by: mbaxter <meredith@oplabs.co>