Added GitHub Actions jobs for SSSE3 and AVX targets.

The targets verify the respective code paths in SIMD algorithms.
The recently added SSE2 paths are already tested in the other,
unspecialized jobs.

Also added jobs to compile tests with BOOST_UUID_TO_FROM_CHARS_X86_USE_ZMM
and BOOST_UUID_FROM_CHARS_X86_USE_VPERMI2B experimental macros defined.

.github/workflows/ci.yml

@@ -92,6 +92,14 @@ jobs:
             os: ubuntu-latest
             install: g++-15-multilib
             address-model: 32,64
+          - toolset: gcc-13
+            cxxstd: "11,14,17,20,2b"
+            instruction-set: core2
+            cpu-requirements: [ ssse3 ]
+            os: ubuntu-latest
+            container: ubuntu:24.04
+            install: g++-13-multilib
+            address-model: 32,64
           - toolset: gcc-13
             cxxstd: "11,14,17,20,2b"
             instruction-set: nehalem
@@ -100,6 +108,14 @@ jobs:
             container: ubuntu:24.04
             install: g++-13-multilib
             address-model: 32,64
+          - toolset: gcc-13
+            cxxstd: "11,14,17,20,2b"
+            instruction-set: sandy-bridge
+            cpu-requirements: [ avx ]
+            os: ubuntu-latest
+            container: ubuntu:24.04
+            install: g++-13-multilib
+            address-model: 32,64
           - toolset: gcc-13
             cxxstd: "11,14,17,20,2b"
             instruction-set: haswell
@@ -124,6 +140,16 @@ jobs:
             container: ubuntu:24.04
             install: g++-13-multilib
             address-model: 32,64
+            # Experimental features
+          - toolset: gcc-13
+            cxxstd: "11,14,17,20,2b"
+            instruction-set: rocketlake
+            cpu-requirements: [ avx512f, avx512cd, avx512vl, avx512dq, avx512bw, avx512vbmi, avx512_vbmi2, avx512_bitalg, bmi1, bmi2 ]
+            defines: [ BOOST_UUID_TO_FROM_CHARS_X86_USE_ZMM, BOOST_UUID_FROM_CHARS_X86_USE_VPERMI2B ]
+            os: ubuntu-latest
+            container: ubuntu:24.04
+            install: g++-13-multilib
+            address-model: 32,64
           - toolset: clang
             compiler: clang++-3.9
             cxxstd: "11,14"
@@ -238,6 +264,14 @@ jobs:
             container: ubuntu:25.10
             os: ubuntu-latest
             install: clang-21
+          - toolset: clang
+            compiler: clang++-17
+            cxxstd: "11,14,17,20,2b"
+            instruction-set: core2
+            cpu-requirements: [ ssse3 ]
+            container: ubuntu:24.04
+            os: ubuntu-latest
+            install: clang-17
           - toolset: clang
             compiler: clang++-17
             cxxstd: "11,14,17,20,2b"
@@ -246,6 +280,14 @@ jobs:
             container: ubuntu:24.04
             os: ubuntu-latest
             install: clang-17
+          - toolset: clang
+            compiler: clang++-17
+            cxxstd: "11,14,17,20,2b"
+            instruction-set: sandy-bridge
+            cpu-requirements: [ avx ]
+            container: ubuntu:24.04
+            os: ubuntu-latest
+            install: clang-17
           - toolset: clang
             compiler: clang++-17
             cxxstd: "11,14,17,20,2b"
@@ -270,6 +312,16 @@ jobs:
             container: ubuntu:24.04
             os: ubuntu-latest
             install: clang-17
+            # Experimental features
+          - toolset: clang
+            compiler: clang++-17
+            cxxstd: "11,14,17,20,2b"
+            instruction-set: rocketlake
+            cpu-requirements: [ avx512f, avx512cd, avx512vl, avx512dq, avx512bw, avx512vbmi, avx512_vbmi2, avx512_bitalg, bmi1, bmi2 ]
+            defines: [ BOOST_UUID_TO_FROM_CHARS_X86_USE_ZMM, BOOST_UUID_FROM_CHARS_X86_USE_VPERMI2B ]
+            container: ubuntu:24.04
+            os: ubuntu-latest
+            install: clang-17
           - toolset: clang
             os: macos-14
             cxxstd: "11,14,17,20,2b"
@@ -346,6 +398,7 @@ jobs:
           cd ../boost-root
           ADDRMD=${{matrix.address-model}}
           INSTRUCTION_SET=${{matrix.instruction-set}}
+          b2_args=(-j2 libs/$LIBRARY/test toolset=${{matrix.toolset}} cxxstd=${{matrix.cxxstd}} ${ADDRMD:+address-model=$ADDRMD} ${INSTRUCTION_SET:+instruction-set=$INSTRUCTION_SET} variant=debug,release)
           if [ -n "${{matrix.cpu-requirements}}" ]
           then
             cpu_flags="$(lscpu | grep -F "Flags:" | sed "s/^Flags:\\s*//")";
@@ -360,7 +413,14 @@ jobs:
               fi
             done
           fi
-          ./b2 -j2 libs/$LIBRARY/test toolset=${{matrix.toolset}} cxxstd=${{matrix.cxxstd}} ${ADDRMD:+address-model=$ADDRMD} ${INSTRUCTION_SET:+instruction-set=$INSTRUCTION_SET} variant=debug,release
+          if [ -n "${{matrix.defines}}" ]
+          then
+            for define in ${{join(matrix.defines, ' ')}}
+            do
+              b2_args+=("define=$define")
+            done
+          fi
+          ./b2 "${b2_args[@]}"
 
   windows:
     strategy: