make wasm-common static library
make wasm-common static library

This speeds up the build a little

WebAssembly/wabt,citisolo/wabt,WebAssembly/sexpr-wasm-prototype,citisolo/wabt,WebAssembly/wabt,WebAssembly/wabt,citisolo/wabt,WebAssembly/sexpr-wasm-prototype,WebAssembly/sexpr-wasm-prototype,WebAssembly/wabt,citisolo/wabt,WebAssembly/sexpr-wasm-prototype,WebAssembly/wabt,citisolo/wabt,citisolo/wabt,WebAssembly/sexpr-wasm-prototype,WebAssembly/sexpr-wasm-prototype