Bounds-unchecked WASI guest memory writes

[rennergade]

src/wasmtime/crates/lind-common/src/lib.rs:71-82, 319-345, 372-389, 395-406

Host functions args_get, environ_get, and random_get write to guest memory at base + offset without verifying against memory.data_size(). Signed integer lengths can also become huge unsigned values.

[qianxichen233]

when verify a memory address, there are two possible scenario to verify:

1. if the address writes on PROT_NONE region (lind unmap-ed region)
2. if the address exceeds the entire lind memory boundary (4GB boundary)

the issue is talking about the second scenario
do we want to verify the first scenario as well? This requires the access to vmmap to validate memory for every memory writes