travis: Add LLVM-8 build

Reviewer: Tom Stellard
Signed-off-by: Jan Vesely <jan.vesely@rutgers.edu>

git-svn-id: https://llvm.org/svn/llvm-project/libclc/trunk@357125 91177308-0d34-0410-b5e6-96231b3b80d8

.travis.yml

diff --git a/.travis.yml b/.travis.yml
index 89c7585..0c99920 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -87,6 +87,23 @@
             - llvm-7-dev
             - clang-7
     - env:
+        - LABEL="make gcc LLVM-8"
+        - LLVM_VERSION=8
+        - CHECK_FILES="barts-r600--.bc cayman-r600--.bc cedar-r600--.bc cypress-r600--.bc tahiti-amdgcn--.bc amdgcn--amdhsa.bc tahiti-amdgcn-mesa-mesa3d.bc nvptx--nvidiacl.bc nvptx64--nvidiacl.bc"
+        - MATRIX_EVAL="CC=gcc-6 && CXX=g++-6"
+      addons:
+        apt:
+          sources:
+            - sourceline: 'deb http://apt.llvm.org/trusty/ llvm-toolchain-trusty-8 main'
+              key_url: https://apt.llvm.org/llvm-snapshot.gpg.key
+            - ubuntu-toolchain-r-test
+          packages:
+            - libedit-dev
+            - g++-6
+            # From sources above
+            - llvm-8-dev
+            - clang-8
+    - env:
         - LABEL="cmake gcc LLVM-3.9"
         - LLVM_VERSION=3.9
         - CHECK_FILES="barts-r600--.bc cayman-r600--.bc cedar-r600--.bc cypress-r600--.bc tahiti-amdgcn--.bc amdgcn--amdhsa.bc nvptx--nvidiacl.bc nvptx64--nvidiacl.bc"
@@ -163,6 +180,23 @@
             # From sources above
             - llvm-7-dev
             - clang-7
+    - env:
+        - LABEL="cmake gcc LLVM-8"
+        - LLVM_VERSION=8
+        - CHECK_FILES="barts-r600--.bc cayman-r600--.bc cedar-r600--.bc cypress-r600--.bc tahiti-amdgcn--.bc amdgcn--amdhsa.bc tahiti-amdgcn-mesa-mesa3d.bc nvptx--nvidiacl.bc nvptx64--nvidiacl.bc"
+        - MATRIX_EVAL="CC=gcc-6 && CXX=g++-6"
+      addons:
+        apt:
+          sources:
+            - sourceline: 'deb http://apt.llvm.org/trusty/ llvm-toolchain-trusty-8 main'
+              key_url: https://apt.llvm.org/llvm-snapshot.gpg.key
+            - ubuntu-toolchain-r-test
+          packages:
+            - libedit-dev
+            - g++-6
+            # From sources above
+            - llvm-8-dev
+            - clang-8
 
 before_install:
     - eval "${MATRIX_EVAL}"