intrinsic-test: Adding x86 behavioural testing.

ci/docker/x86_64-unknown-linux-gnu/Dockerfile

@@ -6,7 +6,11 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   make \
   ca-certificates \
   wget \
-  xz-utils
+  xz-utils \
+  clang \
+  libstdc++-14-dev \
+  build-essential \
+  lld
 
 RUN wget http://ci-mirrors.rust-lang.org/stdarch/sde-external-9.58.0-2025-06-16-lin.tar.xz -O sde.tar.xz
 RUN mkdir intel-sde

ci/run.sh

@@ -91,7 +91,13 @@ fi
 # Test targets compiled with extra features.
 case ${TARGET} in
     x86_64-unknown-linux-gnu)
+        TEST_CPPFLAGS="-fuse-ld=lld -I/usr/include/x86_64-linux-gnu/"
+        TEST_CXX_COMPILER="clang++"
+        TEST_RUNNER="${CARGO_TARGET_X86_64_UNKNOWN_LINUX_GNU_RUNNER}"
+        TEST_SKIP_INTRINSICS=crates/intrinsic-test/missing_x86.txt
         export STDARCH_DISABLE_ASSERT_INSTR=1
+        PATH="$PATH":"$(pwd)"/c_programs
+        export PATH
 
         export RUSTFLAGS="${RUSTFLAGS} -C target-feature=+avx"
         cargo_test "${PROFILE}"
@@ -181,6 +187,21 @@ case "${TARGET}" in
             --linker "${CARGO_TARGET_AARCH64_BE_UNKNOWN_LINUX_GNU_LINKER}" \
             --cxx-toolchain-dir "${AARCH64_BE_TOOLCHAIN}"
         ;;
+
+    x86_64-unknown-linux-gnu*)
+        # `CARGO_TARGET_X86_64_UNKNOWN_LINUX_GNU_RUNNER` is not necessary for `intrinsic-test`
+        # because the binary needs to run directly on the host.
+        # Hence the use of `env -u`.
+        env -u CARGO_TARGET_X86_64_UNKNOWN_LINUX_GNU_RUNNER \
+            CPPFLAGS="${TEST_CPPFLAGS}" RUSTFLAGS="${HOST_RUSTFLAGS}" \
+            RUST_LOG=warn RUST_BACKTRACE=1 \
+            cargo run "${INTRINSIC_TEST}" "${PROFILE}"  \
+            --bin intrinsic-test -- intrinsics_data/x86-intel.xml \
+            --runner "${TEST_RUNNER}" \
+            --skip "${TEST_SKIP_INTRINSICS}" \
+            --cppcompiler "${TEST_CXX_COMPILER}" \
+            --target "${TARGET}"
+        ;;
      *)
         ;;
 esac

crates/intrinsic-test/Cargo.toml

@@ -19,3 +19,6 @@ pretty_env_logger = "0.5.0"
 rayon = "1.5.0"
 diff = "0.1.12"
 itertools = "0.14.0"
+quick-xml = { version = "0.37.5", features = ["serialize", "overlapped-lists"] }
+serde-xml-rs = "0.8.0"
+regex = "1.11.1"