[wasm-decompile] Fix repeated pre-declarations (#1666)
[wasm-decompile] Fix repeated pre-declarations (#1666)

See https://github.com/WebAssembly/wabt/issues/1565
And https://github.com/WebAssembly/wabt/issues/1665
This could be done better, but for now is sufficient.
WebAssembly/sexpr-wasm-prototype,WebAssembly/sexpr-wasm-prototype,WebAssembly/wabt,WebAssembly/sexpr-wasm-prototype,WebAssembly/sexpr-wasm-prototype,WebAssembly/wabt,WebAssembly/sexpr-wasm-prototype,WebAssembly/sexpr-wasm-prototype,WebAssembly/wabt,WebAssembly/wabt,WebAssembly/wabt