10b5cc50c3
This commit reduces the size of `InstructionAddressMap` from 24 bytes to 8 bytes by dropping the `code_len` field and reducing `code_offset` to `u32` instead of `usize`. The intention is to primarily make the in-memory version take up less space, and the hunch is that the `code_len` is largely not necessary since most entries in this map are always adjacent to one another. The `code_len` field is now implied by the `code_offset` field of the next entry in the map. This isn't as big of an improvement to serialized module size as #2321 or #2322, primarily because of the switch to variable-length encoding. Despite this though it shaves about 10MB off the encoded size of the module from #2318
This is the wasmtime-environ crate, which contains the implementations
of the ModuleEnvironment and FuncEnvironment traits from
cranelift-wasm. They effectively
implement an ABI for basic wasm compilation that defines how linear memories
are allocated, how indirect calls work, and other details. They can be used
for JITing, native object files, or other purposes.