[Java] Add OS X native build.

Author: mjpt777

.travis.yml

@@ -29,96 +29,102 @@ matrix:
       os: linux
       script: ./gradlew
 
-    - env: COMPILER=clang++-4.0
+    - env: COMPILER=g++-6
       language: cpp
-      compiler: clang
+      compiler: gcc
       os: linux
       addons:
         apt:
           packages:
-            - clang-4.0
-            - libstdc++-6-dev
+            - g++-6
             - libsparsehash-dev
           sources:
             - ubuntu-toolchain-r-test
-            - llvm-toolchain-trusty-4.0
       before_script: ./gradlew
       script: ./cppbuild/cppbuild
 
-    - env: COMPILER=clang++-5.0
+    - env: COMPILER=g++-7
       language: cpp
-      compiler: clang
+      compiler: gcc
       os: linux
       addons:
         apt:
           packages:
-            - clang-5.0
-            - libstdc++-7-dev
+            - g++-7
             - libsparsehash-dev
           sources:
             - ubuntu-toolchain-r-test
-            - llvm-toolchain-trusty-5.0
       before_script: ./gradlew
       script: ./cppbuild/cppbuild
 
-    - env: COMPILER=clang++-6.0
+    - env: COMPILER=g++-8
       language: cpp
-      compiler: clang
+      compiler: gcc
       os: linux
       addons:
         apt:
           packages:
-            - clang-6.0
-            - libstdc++-7-dev
+            - g++-8
             - libsparsehash-dev
           sources:
             - ubuntu-toolchain-r-test
-            - llvm-toolchain-trusty-6.0
       before_script: ./gradlew
       script: ./cppbuild/cppbuild
 
-    - env: COMPILER=g++-6
+    - env: COMPILER=clang++-4.0
       language: cpp
-      compiler: gcc
+      compiler: clang
       os: linux
       addons:
         apt:
           packages:
-            - g++-6
+            - clang-4.0
+            - libstdc++-6-dev
             - libsparsehash-dev
           sources:
             - ubuntu-toolchain-r-test
+            - llvm-toolchain-trusty-4.0
       before_script: ./gradlew
       script: ./cppbuild/cppbuild
 
-    - env: COMPILER=g++-7
+    - env: COMPILER=clang++-5.0
       language: cpp
-      compiler: gcc
+      compiler: clang
       os: linux
       addons:
         apt:
           packages:
-            - g++-7
+            - clang-5.0
+            - libstdc++-7-dev
             - libsparsehash-dev
           sources:
             - ubuntu-toolchain-r-test
+            - llvm-toolchain-trusty-5.0
       before_script: ./gradlew
       script: ./cppbuild/cppbuild
 
-    - env: COMPILER=g++-8
+    - env: COMPILER=clang++-6.0
       language: cpp
-      compiler: gcc
+      compiler: clang
       os: linux
       addons:
         apt:
           packages:
-            - g++-8
+            - clang-6.0
+            - libstdc++-7-dev
             - libsparsehash-dev
           sources:
             - ubuntu-toolchain-r-test
+            - llvm-toolchain-trusty-6.0
       before_script: ./gradlew
       script: ./cppbuild/cppbuild
 
+    - env: COMPILER=clang++
+      language: c++
+      compiler: clang
+      os: osx
+      before_script: ./gradlew
+      script: ./cppbuild/cppbuild
 
 before_cache:
   - rm -f  $HOME/.gradle/caches/modules-2/modules-2.lock