Write global mutability into wasm binary (#739)
Write global mutability into wasm binary (#739)

For compatibility with 0xc
Also update opcode for get_global

WebAssembly/binaryen,WebAssembly/binaryen,yurydelendik/binaryen,yurydelendik/binaryen,WebAssembly/binaryen,yurydelendik/binaryen,yurydelendik/binaryen,WebAssembly/binaryen,yurydelendik/binaryen,WebAssembly/binaryen