WIP: Remove binaryen for codegen

[Pangoraw]

This uses WasmCompiler.jl for codegen instead of libbinaryen.

• Rename and publish WasmCompiler.jl (any name ideas?)
• Test GC stuff
• Primitive error handling

Note

This is pretty much work in progress, expect very little to work.

But it can compile relu !

julia> using WebAssemblyCompiler, WasmCompiler

julia> relu(x) = ifelse(x < zero(x), zero(x), x)
relu (generic function with 1 method)

julia> compile((relu, Float32); optimize=true)
(module
  (func $relu (param i32 f32) (result f32)
    (local i32 f32)
    block
      local.get 1
      f32.const 0.0
      f32.lt
      local.set 2
      f32.const 0.0
      local.get 1
      local.get 2
      select
      local.set 3
      local.get 3
      return
      return
    end
    unreachable
  )
  (export "relu" (func $relu))
)

julia> instance = WasmCompiler.Interpreter.instantiate(open(WC.wread, "foo.wasm"  ));
       wasm_relu = WasmCompiler.Interpreter.exports(instance).relu
       wasm_relu(Int32(0), -1f0), wasm_relu(Int32(0), 10f0)
(Any[0.0f0], Any[10.0f0])

[tshort]

Naming is tough, but I don't see anything wrong with WasmCompiler.jl.