build(cmake): link migrated Rust code into native libraries

Build a configuration-matched Cargo static library during CMake builds and
join its object members into the generated static libzstd archive.  A single
flattened archive avoids C-to-Rust and Rust-to-C archive-order failures for
external consumers.

Shared builds whole-archive the Cargo output so Rust-only public ABI exports
remain visible.  The configuration also follows partial compression and
decompression builds, forced HUF modes, and supported 32-bit Linux targets.
Dedicated CTest smoke consumers cover both linkage forms.

Test Plan:
- configure and build fresh static and shared CMake smoke targets
- ctest -R 'rustLibSmoke(Static|Shared)' --output-on-failure
- cargo clippy, cargo clippy --benches, cargo clippy --tests, and nightly fmt
- validate partial, forced-HUF, i686, install, and incremental build paths

Refs: build/cmake/lib/merge_rust_archive.cmake

build/cmake/tests/CMakeLists.txt

@@ -90,6 +90,23 @@ AddTestFlagsOption(ZSTD_ZSTREAM_FLAGS "$ENV{ZSTREAM_TESTTIME} $ENV{FUZZER_FLAGS}
     "Semicolon-separated list of flags to pass to the zstreamtest test (see `zstreamtest -h` for usage)")
 add_test(NAME zstreamtest COMMAND "$<TARGET_FILE:zstreamtest>" ${ZSTD_ZSTREAM_FLAGS})
 
+# Verify that a consumer can link the completed static archive alone: migrated
+# Rust objects and the C code they call must not remain separate archives.  The
+# shared variant also checks that whole-archive linking retains Rust-only ABI
+# exports such as the DDict lifecycle functions.
+add_executable(rustLibSmokeStatic ${TESTS_DIR}/rustLibSmoke.c)
+target_link_libraries(rustLibSmokeStatic libzstd_static)
+add_test(NAME rustLibSmokeStatic COMMAND "$<TARGET_FILE:rustLibSmokeStatic>")
+if(ZSTD_BUILD_SHARED)
+    add_executable(rustLibSmokeShared ${TESTS_DIR}/rustLibSmoke.c)
+    target_link_libraries(rustLibSmokeShared libzstd_shared)
+    if(UNIX)
+        set_property(TARGET rustLibSmokeShared APPEND PROPERTY
+            BUILD_RPATH "$<TARGET_FILE_DIR:libzstd_shared>")
+        add_test(NAME rustLibSmokeShared COMMAND "$<TARGET_FILE:rustLibSmokeShared>")
+    endif()
+endif()
+
 #
 # playTests.sh
 #