Fix some portability issues in interp-wasi.cc (#1480)
Fix some portability issues in interp-wasi.cc (#1480)

_Static_assert and _Alignof aren't defined everywhere. Also use PRIu64 format specifier where needed.

Co-authored-by: Ben Smith <261286bbb9d94d29e339db664b0a1cf0ef22a6d7@chromium.org>
WebAssembly/sexpr-wasm-prototype,WebAssembly/sexpr-wasm-prototype,WebAssembly/wabt,WebAssembly/sexpr-wasm-prototype,WebAssembly/wabt,WebAssembly/sexpr-wasm-prototype,WebAssembly/sexpr-wasm-prototype,WebAssembly/sexpr-wasm-prototype,WebAssembly/wabt,WebAssembly/wabt,WebAssembly/wabt