[travis] Fix build (rust-lang#357)

.travis.yml

@@ -1,14 +1,12 @@
 language: rust
+
 addons:
-    apt:
-      sources:
-        - llvm-toolchain-precise-3.5
-        - llvm-toolchain-precise-3.8
-      packages:
-        - libclang-3.5-dev
-        - llvm-3.5-dev
-        - libclang-3.8-dev
-        - llvm-3.8-dev
+  apt:
+    sources:
+      - ubuntu-toolchain-r-test
+    packages:
+      - gcc-5
+
 env:
   - LLVM_VERSION=3.5
   - LLVM_VERSION=3.8
@@ -18,6 +16,7 @@ rust:
 os:
   - osx
   - linux
+
 matrix:
   allow_failures:
     - rust: nightly
@@ -41,25 +40,23 @@ cache: cargo
 
 before_install:
   -
+    set -e;
     if [ "${TRAVIS_OS_NAME}" = "osx" ]; then
       if [ "${LLVM_VERSION}" != "devtools" ]; then
         brew update >/dev/null;
         brew install llvm3${LLVM_VERSION#3.};
-      fi
-    fi
-
-before_script:
-  -
-    if [ "${TRAVIS_OS_NAME}" = "linux" ]; then
-      export LIBCLANG_PATH=/usr/lib/llvm-${LLVM_VERSION}/lib;
-    elif [ "${TRAVIS_OS_NAME}" = "osx" ]; then
-      if [ "${LLVM_VERSION}" = "devtools" ]; then
-        export LIBCLANG_PATH=/Library/Developer/CommandLineTools/usr/lib;
-      else
         export LIBCLANG_PATH=`brew --prefix llvm3${LLVM_VERSION#3.}`/lib/llvm-${LLVM_VERSION}/lib;
+      else
+        export LIBCLANG_PATH=/Library/Developer/CommandLineTools/usr/lib;
       fi
+    else
+      export LLVM=clang+llvm-${LLVM_VERSION}-x86_64-linux-gnu-ubuntu-14.04;
+      wget http://llvm.org/releases/${LLVM_VERSION}/${LLVM}.tar.xz ;
+      mkdir llvm;
+      tar -xf ${LLVM}.tar.xz -C llvm --strip-components=1;
+      export LIBCLANG_PATH=`pwd`/llvm/lib;
     fi
-  - echo $LIBCLANG_PATH
+    echo $LIBCLANG_PATH;
 
 after_success: |
   [ "${TRAVIS_RUST_VERSION}" = "stable" ] &&