fix: make demo container building optional via cmake option

Add OCRE_BUILD_DEMO_CONTAINERS option (default ON) to control whether
demo_containers.cmake is included. This allows building the Ocre runtime
on platforms where WASI SDK is not available (e.g. riscv64), by passing
-DOCRE_BUILD_DEMO_CONTAINERS=OFF.

The demo containers require the ocre-sdk submodule which uses WASI SDK
to compile C to WebAssembly. WASI SDK ships pre-built binaries for
x86_64 and arm64 only, so the demo build fails on other architectures.

The runtime itself (ocre_mini, ocre_demo, ocre_cmd) builds and runs
correctly on riscv64 without this dependency.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Signed-off-by: Bruno Verachten <gounthar@gmail.com>

Author: 2 people

CMakeLists.txt

@@ -13,7 +13,11 @@ set(CMAKE_C_STANDARD 99)
 
 set(WAMR_BUILD_PLATFORM linux)
 
-include (src/samples/demo/demo_containers.cmake)
+option(OCRE_BUILD_DEMO_CONTAINERS "Build demo containers from ocre-sdk (requires WASI SDK)" ON)
+
+if(OCRE_BUILD_DEMO_CONTAINERS)
+    include (src/samples/demo/demo_containers.cmake)
+endif()
 
 # uthash
 add_subdirectory(src/uthash)