ci: expand Travis-CI build matrix and use two parallel build jobs

Change-Id: I7dbba5bcd63274daa9b0da2ee9d631a55c1eca9e
diff --git a/.travis.yml b/.travis.yml
index 508b081..f27e3a3 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,26 +3,135 @@
 env:
   global:
     - JOB_NAME=limited-build
+    - WAF_JOBS=2
+
 matrix:
   include:
+    # Linux/gcc
     - os: linux
       dist: trusty
       env:
-        - CXX=g++
+        - CXX=g++-4.8
+        - NODE_LABELS="Linux Ubuntu Ubuntu-14.04"
+        - BUILD_WITH_ASAN=yes
+    - os: linux
+      dist: trusty
+      addons:
+        apt:
+          sources: ubuntu-toolchain-r-test
+          packages: g++-4.9
+      env:
+        - CXX=g++-4.9
+        - NODE_LABELS="Linux Ubuntu Ubuntu-14.04"
+        - BUILD_WITH_ASAN=yes
+    - os: linux
+      dist: trusty
+      addons:
+        apt:
+          sources: ubuntu-toolchain-r-test
+          packages: g++-5
+      env:
+        - CXX=g++-5
+        - NODE_LABELS="Linux Ubuntu Ubuntu-14.04"
+        - BUILD_WITH_ASAN=yes
+    - os: linux
+      dist: trusty
+      addons:
+        apt:
+          sources: ubuntu-toolchain-r-test
+          packages: g++-6
+      env:
+        - CXX=g++-6
+        - NODE_LABELS="Linux Ubuntu Ubuntu-14.04"
+        - BUILD_WITH_ASAN=yes
+    - os: linux
+      dist: trusty
+      addons:
+        apt:
+          sources: ubuntu-toolchain-r-test
+          packages: g++-7
+      env:
+        - CXX=g++-7
+        - NODE_LABELS="Linux Ubuntu Ubuntu-14.04"
+        - BUILD_WITH_ASAN=yes
+
+    # Linux/clang
+    - os: linux
+      dist: trusty
+      addons:
+        apt:
+          packages: clang-3.5
+      env:
+        - CXX=clang++-3.5
+        - NODE_LABELS="Linux Ubuntu Ubuntu-14.04"
+        - BUILD_WITH_ASAN=yes
+    - os: linux
+      dist: trusty
+      addons:
+        apt:
+          packages: clang-3.6
+      env:
+        - CXX=clang++-3.6
+        - NODE_LABELS="Linux Ubuntu Ubuntu-14.04"
+        - BUILD_WITH_ASAN=yes
+    - os: linux
+      dist: trusty
+      addons:
+        apt:
+          sources:
+            - llvm-toolchain-precise-3.7
+            - ubuntu-toolchain-r-test
+          packages: clang-3.7
+      env:
+        - CXX=clang++-3.7
         - NODE_LABELS="Linux Ubuntu Ubuntu-14.04"
     - os: linux
       dist: trusty
+      addons:
+        apt:
+          sources:
+            - llvm-toolchain-precise-3.8
+            - ubuntu-toolchain-r-test
+          packages: clang-3.8
       env:
-        - CXX=clang++
+        - CXX=clang++-3.8
         - NODE_LABELS="Linux Ubuntu Ubuntu-14.04"
+        - BUILD_WITH_ASAN=yes
+    - os: linux
+      dist: trusty
+      addons:
+        apt:
+          sources: llvm-toolchain-trusty-3.9
+          packages: clang-3.9
+      env:
+        - CXX=clang++-3.9
+        - NODE_LABELS="Linux Ubuntu Ubuntu-14.04"
+    - os: linux
+      dist: trusty
+      addons:
+        apt:
+          sources: llvm-toolchain-trusty-4.0
+          packages: clang-4.0
+      env:
+        - CXX=clang++-4.0
+        - NODE_LABELS="Linux Ubuntu Ubuntu-14.04"
+        - BUILD_WITH_ASAN=yes
+
+    # macOS/clang
+    # https://docs.travis-ci.com/user/osx-ci-environment/#OS-X-Version
     - os: osx
-      osx_image: xcode8.2
+      osx_image: xcode7.3
       env:
-        - CXX=clang++
+        - NODE_LABELS="OSX OSX-10.11"
+        - BUILD_WITH_ASAN=yes
+    - os: osx
+      osx_image: xcode8.3
+      env:
         - NODE_LABELS="OSX OSX-10.12"
-notifications:
-  email:
-    on_success: always
-    on_failure: always
+        - BUILD_WITH_ASAN=yes
+
+before_script:
+  - ${CXX:-c++} --version
+
 script:
   - ./.jenkins