Auto merge of #29159 - arcnmx:travis-trusty, r=alexcrichton

Moves back away from docker but still uses the GCE infrastructure with a system-installed LLVM. 

See http://docs.travis-ci.com/user/trusty-ci-environment/

.travis.yml

@@ -1,7 +1,6 @@
-language: c
+language: generic
 sudo: required
-services:
-  - docker
+dist: trusty
 
 # LLVM takes awhile to check out and otherwise we'll manage the submodules in
 # our configure script, so disable auto submodule management.
@@ -9,14 +8,15 @@ git:
   submodules: false
 
 before_install:
-  - docker build -t rust -f src/etc/Dockerfile src/etc
+  - echo 0 | sudo tee /proc/sys/net/ipv6/conf/lo/disable_ipv6
+  - echo 'deb http://llvm.org/apt/trusty/ llvm-toolchain-trusty-3.7 main' | sudo tee -a /etc/apt/sources.list
+  - echo 'deb-src http://llvm.org/apt/trusty/ llvm-toolchain-trusty-3.7 main' | sudo tee -a /etc/apt/sources.list
+  - sudo apt-get update
+  - sudo apt-get --force-yes install curl make g++ python2.7 git zlib1g-dev libedit-dev llvm-3.7-tools
+
 script:
-  - docker run --privileged -tv `pwd`:/build rust
-    sh -c "
-      ./configure --llvm-root=/usr/lib/llvm-3.7 &&
-      make tidy &&
-      make check -j4
-    "
+  - ./configure --llvm-root=/usr/lib/llvm-3.7
+  - make tidy && make check-notidy -j4
 
 # Real testing happens on http://buildbot.rust-lang.org/
 #

src/etc/Dockerfile

@@ -1,12 +0,0 @@
-FROM ubuntu:latest
-
-RUN echo 'deb http://llvm.org/apt/trusty/ llvm-toolchain-trusty-3.7 main' | \
-        sudo tee -a /etc/apt/sources.list
-RUN echo 'deb-src http://llvm.org/apt/trusty/ llvm-toolchain-trusty-3.7 main' | \
-        sudo tee -a /etc/apt/sources.list
-RUN apt-get update
-RUN apt-get -y install curl make g++ python2.7 git zlib1g-dev libedit-dev
-RUN apt-get -y --force-yes install llvm-3.7-tools
-
-RUN mkdir /build
-WORKDIR /build