apu: Add new DSP56300 emulator with JIT execution engine

- Fixes a few bugs in the existing C interpreter
- Adds a state abstraction layer to switch between engines at runtime
  and maintain snapshot compatibility

scripts/archive-source.sh

@@ -122,4 +122,15 @@ for sp in "${subprojects[@]}"; do
     tar --append --file "$tar_file" --exclude=.git --transform "s,^./,$tar_prefix," ./subprojects/"$(subproject_dir $sp)"
     test $? -ne 0 && error "failed to append subproject $sp to $tar_file"
 done
+
+# Pre-download dsp56300 pre-built libraries for offline builds (e.g. PPA).
+dsp56300_version=$(sed -n "s/^project.*version: *'\([^']*\)'.*/\1/p" subprojects/dsp56300/meson.build)
+for target in x86_64-unknown-linux-gnu aarch64-unknown-linux-gnu; do
+    archive="dsp56300-${dsp56300_version}-${target}.tar.gz"
+    curl -fsSL "https://github.com/mborgerson/dsp56300/releases/download/v${dsp56300_version}/${archive}" \
+        -o "subprojects/dsp56300/${archive}"
+    tar --append --file "$tar_file" --transform "s,^./,$tar_prefix," "./subprojects/dsp56300/${archive}"
+    rm "subprojects/dsp56300/${archive}"
+done
+
 exit 0

scripts/gen-license.py

@@ -510,6 +510,17 @@ LIBS = [
         platform={windows},
         submodule=Submodule("subprojects/curl.wrap"),
     ),
+    Lib(
+        "dsp56300",
+        "https://github.com/mborgerson/dsp56300",
+        mit,
+        # Note: This URL points to the dsp56300 license, but the distributed library includes
+        # additional dependencies. The license file at licenses/dsp56300.license.txt contains
+        # the dsp56300 license as well as its dependencies.
+        "https://raw.githubusercontent.com/mborgerson/dsp56300/refs/heads/main/LICENSE",
+        ships_static=all_platforms,
+        version="0.1.3",
+    ),
 ]