The added Dockerfile is based on the emsdk image, which includes the
Emscripten toolchain. It also cross-compiles the necessary dependencies
(glib, libffi, pixman, and zlib) for the Emscripten target environment.
Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
Link: https://lore.kernel.org/r/8bed6e9d46ef09328a87320928b5dec575d1e435.1745820062.git.ktokunaga.mail@gmail.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>