cmake: add debug option
cmake: add debug option

Use -DCMAKE_BUILD_TYPE=Debug to use the debug build (by default you get Release). I was getting tired of manually changing the cmake file.

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