Fix issue of travis CI test and update spirv branch name

Author: fzou1

.travis.yml

@@ -23,7 +23,7 @@ env:
 
 before-install:
   - curl -L "https://apt.llvm.org/llvm-snapshot.gpg.key" | sudo apt-key add -
-  - echo "deb http://apt.llvm.org/bionic/ llvm-toolchain-bionic main" | sudo tee -a ${TRAVIS_ROOT}/etc/apt/sources.list
+  - echo "deb http://apt.llvm.org/bionic/ llvm-toolchain-bionic-11 main" | sudo tee -a ${TRAVIS_ROOT}/etc/apt/sources.list
   - sudo apt-get update
   - sudo apt-get -yq --no-install-suggests --no-install-recommends install
       llvm-${LLVM_VERSION}-dev

CMakeLists.txt

@@ -120,8 +120,7 @@ if(NOT USE_PREBUILT_LLVM)
     endif()
 
 
-    # TODO: update after spirv translator branch for llvm 11 is created
-    set(SPIRV_BASE_REVISION master)
+    set(SPIRV_BASE_REVISION llvm_release_110)
     set(TARGET_BRANCH "ocl-open-110")
 
     apply_patches(${CLANG_SOURCE_DIR}