Switch clang-release to overlay convention

.orchestra/config/components.yml

 #@ load("@ytt:template", "template")
 #@ load("@ytt:data", "data")
 
-#@ load("/components/clang_release.lib.yml", "clang_release_component")
 #@ load("/components/glib.lib.yml", "glib_component")
 #@ load("/components/glibc.lib.yml", "glibc_component")
 #@ load("/components/qemu.lib.yml", "qemu_component")
@@ -45,7 +44,6 @@
 
 #@ load("/global_options.lib.yml", "options")
 components:
-  clang-release: #@ clang_release_component
   glib: #@ glib_component
   glibc: #@ glibc_component
   qemu: #@ qemu_component

.orchestra/config/components/clang_release.lib.yml

-#@ load("/components/llvm_common.lib.yml", "configure_llvm")
-#@ load("/lib/create_component.lib.yml", "single_build_component")
-
-#@ load("/global_options.lib.yml", "options")
-
----
-#@ def cmake_opts():
-- -DLLVM_ENABLE_PROJECTS="clang;compiler-rt;libcxxabi;libcxx;clang-tools-extra"
-- -DBUILD_SHARED_LIBS=OFF
-#@ end
-
-#@yaml/text-templated-strings
----
-#@ def _clang_release():
-#@    source_url = "https://github.com/llvm/llvm-project/archive/llvmorg-" + options["clang_release_version"] + ".tar.gz"
-builds:
-  default:
-    configure: |
-      extract.sh --into "$BUILD_DIR/source" "(@= source_url @)"
-      sed -i 's|GIT_FOUND|FALSE|g' "$BUILD_DIR/source/llvm/cmake/modules/VersionFromVCS.cmake"
-      (@= configure_llvm(cmake_build_type="Release", cflags=" ", additional_cmake_options=cmake_opts(), source_dir="$BUILD_DIR/source") @)
-    install: |
-      cd "$BUILD_DIR"
-
-      ninja install
-
-      rm "${DESTDIR}${ORCHESTRA_ROOT}/lib64/libc++.so" || true
-      echo 'INPUT(libc++.so.1 -lc++abi -lpthread)' > "${DESTDIR}${ORCHESTRA_ROOT}/lib64/libc++.so"
-
-      if test -z "$DESTDIR"; then
-        echo "Installing clang-release which will clobber LLVM!"
-      else
-        find ${DESTDIR}${ORCHESTRA_ROOT}/lib* -maxdepth 1 -not -type d \( -name libLLVM* -or -name libclang* \) -delete;
-        rm ${DESTDIR}${ORCHESTRA_ROOT}/bin/opt || true
-        rm ${DESTDIR}${ORCHESTRA_ROOT}/bin/llvm-config || true
-        rm -rf ${DESTDIR}${ORCHESTRA_ROOT}/lib*/cmake/ || true
-        rm -rf ${DESTDIR}${ORCHESTRA_ROOT}/include/clang/ || true
-        rm -rf ${DESTDIR}${ORCHESTRA_ROOT}/include/clang-c/ || true
-        rm -rf ${DESTDIR}${ORCHESTRA_ROOT}/include/llvm/ || true
-        rm -rf ${DESTDIR}${ORCHESTRA_ROOT}/include/llvm-c/ || true
-      fi
-    build_dependencies:
-      - cmake
-    dependencies:
-      - toolchain/host/gcc
-      - toolchain/host/binutils
-      - libunwind
-#@ end
-
----
-#@ clang_release_component = _clang_release()

.orchestra/config/components/clang_release.yml

+#@ load("@ytt:overlay", "overlay")
+#@ load("/components/llvm_common.lib.yml", "configure_llvm")
+#@ load("/lib/create_component.lib.yml", "single_build_component")
+
+#@ load("/global_options.lib.yml", "options")
+
+---
+#@ def cmake_opts():
+- -DLLVM_ENABLE_PROJECTS="clang;compiler-rt;libcxxabi;libcxx;clang-tools-extra"
+- -DBUILD_SHARED_LIBS=OFF
+#@ end
+
+#@yaml/text-templated-strings
+---
+#@ def _clang_release_args():
+#@    source_url = "https://github.com/llvm/llvm-project/archive/llvmorg-" + options["clang_release_version"] + ".tar.gz"
+configure: |
+  extract.sh --into "$BUILD_DIR/source" "(@= source_url @)"
+  sed -i 's|GIT_FOUND|FALSE|g' "$BUILD_DIR/source/llvm/cmake/modules/VersionFromVCS.cmake"
+  (@= configure_llvm(cmake_build_type="Release", cflags=" ", additional_cmake_options=cmake_opts(), source_dir="$BUILD_DIR/source") @)
+install: |
+  cd "$BUILD_DIR"
+
+  ninja install
+
+  rm "${DESTDIR}${ORCHESTRA_ROOT}/lib64/libc++.so" || true
+  echo 'INPUT(libc++.so.1 -lc++abi -lpthread)' > "${DESTDIR}${ORCHESTRA_ROOT}/lib64/libc++.so"
+
+  if test -z "$DESTDIR"; then
+    echo "Installing clang-release which will clobber LLVM!"
+  else
+    find ${DESTDIR}${ORCHESTRA_ROOT}/lib* -maxdepth 1 -not -type d \( -name libLLVM* -or -name libclang* \) -delete;
+    rm ${DESTDIR}${ORCHESTRA_ROOT}/bin/opt || true
+    rm ${DESTDIR}${ORCHESTRA_ROOT}/bin/llvm-config || true
+    rm -rf ${DESTDIR}${ORCHESTRA_ROOT}/lib*/cmake/ || true
+    rm -rf ${DESTDIR}${ORCHESTRA_ROOT}/include/clang/ || true
+    rm -rf ${DESTDIR}${ORCHESTRA_ROOT}/include/clang-c/ || true
+    rm -rf ${DESTDIR}${ORCHESTRA_ROOT}/include/llvm/ || true
+    rm -rf ${DESTDIR}${ORCHESTRA_ROOT}/include/llvm-c/ || true
+  fi
+build_dependencies:
+  - cmake
+dependencies:
+  - toolchain/host/gcc
+  - toolchain/host/binutils
+  - libunwind
+#@ end
+
+#@overlay/match by=overlay.all, expects=1
+#@overlay/match-child-defaults missing_ok=True
+---
+components:
+  clang-release: #@ single_build_component(**_clang_release_args())