Almost all languages targeting WebAssembly create imports from
"env" module by default, which means that Emscripten was being
detected even when it wasn't used.
Use "_emscripten_memcpy_big" as a signal, since it's imported
in all WASM modules produced by Emscripten, even as simple as:
EMSCRIPTEN_KEEPALIVE
int
main(int argc, const char** argv) {
return 0;
}
Signed-off-by: Piotr Sikora <piotrsikora@google.com>