Rollup merge of rust-lang#38632 - alexcrichton:trim-travis, r=japaric

Trim down Travis docker images slightly

Two things we no longer need:

* ccache, we now use sccache
* A `/tmp/obj` dir no longer used

Author: alexcrichton

src/ci/docker/arm-android/Dockerfile

@@ -11,7 +11,6 @@ RUN dpkg --add-architecture i386 && \
   python2.7 \
   git \
   cmake \
-  ccache \
   unzip \
   expect \
   openjdk-9-jre \
@@ -50,5 +49,3 @@ ENV RUST_CONFIGURE_ARGS \
       --i686-linux-android-ndk=/android/ndk-x86-9 \
       --aarch64-linux-android-ndk=/android/ndk-aarch64
 ENV XPY_CHECK test --target arm-linux-androideabi
-RUN mkdir /tmp/obj
-RUN chmod 777 /tmp/obj

src/ci/docker/cross/Dockerfile

@@ -9,7 +9,6 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   python2.7 \
   git \
   cmake \
-  ccache \
   sudo \
   gcc-aarch64-linux-gnu libc6-dev-arm64-cross \
   gcc-arm-linux-gnueabi libc6-dev-armel-cross \
@@ -70,6 +69,3 @@ ENV AR_s390x_unknown_linux_gnu=s390x-linux-gnu-ar \
 
 # FIXME(rust-lang/rust#36150): powerpc unfortunately aborts right now
 ENV NO_LLVM_ASSERTIONS=1
-
-RUN mkdir /tmp/obj
-RUN chmod 777 /tmp/obj

src/ci/docker/i686-gnu-nopt/Dockerfile

@@ -9,7 +9,6 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   python2.7 \
   git \
   cmake \
-  ccache \
   sudo \
   gdb \
   xz-utils
@@ -25,5 +24,3 @@ ENTRYPOINT ["/usr/bin/dumb-init", "--"]
 
 ENV RUST_CONFIGURE_ARGS --build=i686-unknown-linux-gnu --disable-optimize-tests
 ENV RUST_CHECK_TARGET check
-RUN mkdir /tmp/obj
-RUN chmod 777 /tmp/obj

src/ci/docker/i686-gnu/Dockerfile

@@ -9,7 +9,6 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   python2.7 \
   git \
   cmake \
-  ccache \
   sudo \
   gdb \
   xz-utils
@@ -25,5 +24,3 @@ ENTRYPOINT ["/usr/bin/dumb-init", "--"]
 
 ENV RUST_CONFIGURE_ARGS --build=i686-unknown-linux-gnu
 ENV RUST_CHECK_TARGET check
-RUN mkdir /tmp/obj
-RUN chmod 777 /tmp/obj

src/ci/docker/x86_64-freebsd/Dockerfile

@@ -9,7 +9,6 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   python2.7 \
   git \
   cmake \
-  ccache \
   sudo \
   bzip2 \
   xz-utils \
@@ -33,5 +32,3 @@ ENV \
 
 ENV RUST_CONFIGURE_ARGS --target=x86_64-unknown-freebsd
 ENV RUST_CHECK_TARGET ""
-RUN mkdir /tmp/obj
-RUN chmod 777 /tmp/obj

src/ci/docker/x86_64-gnu-cargotest/Dockerfile

@@ -9,7 +9,6 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   python2.7 \
   git \
   cmake \
-  ccache \
   libssl-dev \
   sudo \
   xz-utils \
@@ -27,5 +26,3 @@ ENTRYPOINT ["/usr/bin/dumb-init", "--"]
 ENV RUST_CONFIGURE_ARGS --build=x86_64-unknown-linux-gnu
 ENV RUST_CHECK_TARGET check-cargotest
 ENV NO_VENDOR 1
-RUN mkdir /tmp/obj
-RUN chmod 777 /tmp/obj

src/ci/docker/x86_64-gnu-debug/Dockerfile

@@ -9,7 +9,6 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   python2.7 \
   git \
   cmake \
-  ccache \
   sudo \
   gdb \
   xz-utils
@@ -28,5 +27,3 @@ ENV RUST_CONFIGURE_ARGS \
       --enable-debug \
       --enable-optimize
 ENV RUST_CHECK_TARGET ""
-RUN mkdir /tmp/obj
-RUN chmod 777 /tmp/obj

src/ci/docker/x86_64-gnu-llvm-3.7/Dockerfile

@@ -9,7 +9,6 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   python2.7 \
   git \
   cmake \
-  ccache \
   sudo \
   gdb \
   llvm-3.7-tools \
@@ -30,5 +29,3 @@ ENV RUST_CONFIGURE_ARGS \
       --build=x86_64-unknown-linux-gnu \
       --llvm-root=/usr/lib/llvm-3.7
 ENV RUST_CHECK_TARGET check
-RUN mkdir /tmp/obj
-RUN chmod 777 /tmp/obj

src/ci/docker/x86_64-gnu-make/Dockerfile

@@ -9,7 +9,6 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   python2.7 \
   git \
   cmake \
-  ccache \
   sudo \
   gdb \
   xz-utils
@@ -25,5 +24,3 @@ ENTRYPOINT ["/usr/bin/dumb-init", "--"]
 
 ENV RUST_CONFIGURE_ARGS --build=x86_64-unknown-linux-gnu --disable-rustbuild
 ENV RUST_CHECK_TARGET check
-RUN mkdir /tmp/obj
-RUN chmod 777 /tmp/obj

src/ci/docker/x86_64-gnu-nopt/Dockerfile

@@ -9,7 +9,6 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   python2.7 \
   git \
   cmake \
-  ccache \
   sudo \
   gdb \
   xz-utils
@@ -25,5 +24,3 @@ ENTRYPOINT ["/usr/bin/dumb-init", "--"]
 
 ENV RUST_CONFIGURE_ARGS --build=x86_64-unknown-linux-gnu --disable-optimize-tests
 ENV RUST_CHECK_TARGET check
-RUN mkdir /tmp/obj
-RUN chmod 777 /tmp/obj

src/ci/docker/x86_64-gnu/Dockerfile

@@ -9,7 +9,6 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   python2.7 \
   git \
   cmake \
-  ccache \
   sudo \
   gdb \
   xz-utils
@@ -25,5 +24,3 @@ ENTRYPOINT ["/usr/bin/dumb-init", "--"]
 
 ENV RUST_CONFIGURE_ARGS --build=x86_64-unknown-linux-gnu
 ENV RUST_CHECK_TARGET check
-RUN mkdir /tmp/obj
-RUN chmod 777 /tmp/obj

src/ci/docker/x86_64-musl/Dockerfile

@@ -9,7 +9,6 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   python2.7 \
   git \
   cmake \
-  ccache \
   xz-utils \
   sudo \
   gdb
@@ -33,6 +32,3 @@ ENV RUST_CONFIGURE_ARGS \
 ENV RUST_CHECK_TARGET check-stage2-T-x86_64-unknown-linux-musl-H-x86_64-unknown-linux-gnu
 ENV PATH=$PATH:/musl-x86_64/bin
 ENV XPY_CHECK test --target x86_64-unknown-linux-musl
-
-RUN mkdir /tmp/obj
-RUN chmod 777 /tmp/obj