🐛 add memmove shim for wasm builds

[rauhryan]

Summary

• add a freestanding memmove shim for wasm32 builds
• declare memmove alongside the existing memcpy/memset shims
• fixes CI linker failures where clang emits calls to memmove under -nostdlib

Validation

• make CC=/opt/homebrew/opt/llvm/bin/clang
• deno test

[pkg-pr-new]

Open in StackBlitz

npm i https://pkg.pr.new/clayterm@32

commit: d386e17

[cowboyd]

I'm going to approve this, but curious what code is using it?

We need to get a performance suite in here so that we don't end up accidentally degrading performance.