Wasm targets should append lld --stack-first

[fengb]

By default, LLVM adopts this memory model:

|   Globals   |   <-- Stack   |   Heap -->  |++

This means when the stack runs out of space, it will start trampling over global memory before causing a stack overflow.

Appending --stack-first will flip where the stack and the globals are located, so stack overflow will error out immediately instead of corrupting globals.

Rust has made a similar decision: rustwasm/team#81 (comment)

[zigazeljko]

So the only change is adding lj->args.append("--stack-first"); to construct_linker_job_wasm?

If so, I can prepare a pull request.

[fengb]

Yep that should be it.