Check LEB128 encoding fits in destination integer (#408)
Check LEB128 encoding fits in destination integer (#408)

* Check LEB128 encoding fits in destination integer

As found by #404, the insignificant LEB128 bits were silently dropped
when dealing with signed LEB values which tripped UBSAN in hello_world.

This fixes #409.

* Fix typo.

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