build: wrap android clang path for old ndk

Author: Apricityx

.github/workflows/build-android-arm64.yml

@@ -154,7 +154,21 @@ jobs:
           export ANDROID_STL_INCLUDE="${ANDROID_NDK_HOME}/sources/cxx-stl/gnu-libstdc++/4.9/include"
           export ANDROID_STL_INCLUDE_ABI="${ANDROID_NDK_HOME}/sources/cxx-stl/gnu-libstdc++/4.9/libs/arm64-v8a/include"
           export ANDROID_STL_LIB="${ANDROID_NDK_HOME}/sources/cxx-stl/gnu-libstdc++/4.9/libs/arm64-v8a"
-          export ANDROID_LLVM_CXX="${ANDROID_NDK_HOME}/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android${ANDROID_NDK_API_LEVEL}-clang++"
+          export ANDROID_LLVM_BIN="${ANDROID_NDK_HOME}/toolchains/llvm/prebuilt/linux-x86_64/bin"
+          export ANDROID_LLVM_CXX_WRAPPER="${GITHUB_WORKSPACE}/android-clang++"
+          if [ -x "${ANDROID_LLVM_BIN}/aarch64-linux-android${ANDROID_NDK_API_LEVEL}-clang++" ]; then
+            printf '%s\n' '#!/usr/bin/env bash' \
+              "exec \"${ANDROID_LLVM_BIN}/aarch64-linux-android${ANDROID_NDK_API_LEVEL}-clang++\" \"\$@\"" \
+              > "${ANDROID_LLVM_CXX_WRAPPER}"
+          elif [ -x "${ANDROID_LLVM_BIN}/clang++" ]; then
+            printf '%s\n' '#!/usr/bin/env bash' \
+              "exec \"${ANDROID_LLVM_BIN}/clang++\" --target=aarch64-none-linux-android${ANDROID_NDK_API_LEVEL} \"\$@\"" \
+              > "${ANDROID_LLVM_CXX_WRAPPER}"
+          else
+            echo "No usable LLVM clang++ found under ${ANDROID_LLVM_BIN}" >&2
+            exit 1
+          fi
+          chmod +x "${ANDROID_LLVM_CXX_WRAPPER}"
           export JAVA_HOME="${JAVA_HOME_11_X64}"
           export LANG="C.UTF-8"
           export LC_ALL="C.UTF-8"
@@ -173,7 +187,7 @@ jobs:
             -DskipTests \
             -Djavacpp.platform="${ANDROID_PLATFORM}" \
             -Djavacpp.platform.properties="${ANDROID_PLATFORM}" \
-            -Djavacpp.platform.compiler="${ANDROID_LLVM_CXX}" \
+            -Djavacpp.platform.compiler="${ANDROID_LLVM_CXX_WRAPPER}" \
             -Djavacpp.platform.root="${ANDROID_NDK_HOME}" \
             -pl tensorflow-core/tensorflow-core-api \
             -am \