Move long compilations before Go install in Dockerfile

Now we can avoid long compilations on Go update.

Signed-off-by: Alexander Morozov <lk4d4@docker.com>

Dockerfile

@@ -86,6 +86,32 @@ RUN cd /usr/local/lvm2 \
 	&& make install_device-mapper
 # see https://git.fedorahosted.org/cgit/lvm2.git/tree/INSTALL
 
+# Configure the container for OSX cross compilation
+ENV OSX_SDK MacOSX10.11.sdk
+RUN set -x \
+	&& export OSXCROSS_PATH="/osxcross" \
+	&& git clone --depth 1 https://github.com/tpoechtrager/osxcross.git $OSXCROSS_PATH \
+	&& curl -sSL https://s3.dockerproject.org/darwin/${OSX_SDK}.tar.xz -o "${OSXCROSS_PATH}/tarballs/${OSX_SDK}.tar.xz" \
+	&& UNATTENDED=yes OSX_VERSION_MIN=10.6 ${OSXCROSS_PATH}/build.sh
+ENV PATH /osxcross/target/bin:$PATH
+
+# install seccomp
+# this can be changed to the ubuntu package libseccomp-dev if dockerinit is removed,
+# we need libseccomp.a (which the package does not provide) for dockerinit
+ENV SECCOMP_VERSION 2.2.3
+RUN set -x \
+	&& export SECCOMP_PATH="$(mktemp -d)" \
+	&& curl -fsSL "https://github.com/seccomp/libseccomp/releases/download/v${SECCOMP_VERSION}/libseccomp-${SECCOMP_VERSION}.tar.gz" \
+		| tar -xzC "$SECCOMP_PATH" --strip-components=1 \
+	&& ( \
+		cd "$SECCOMP_PATH" \
+		&& ./configure --prefix=/usr/local \
+		&& make \
+		&& make install \
+		&& ldconfig \
+	) \
+	&& rm -rf "$SECCOMP_PATH"
+
 # Install Go
 # IMPORTANT: If the version of Go is updated, the Windows to Linux CI machines
 #            will need updating, to avoid errors. Ping #docker-maintainers on IRC 
@@ -124,32 +150,6 @@ RUN git clone https://github.com/golang/lint.git /go/src/github.com/golang/lint
 	&& (cd /go/src/github.com/golang/lint && git checkout -q $GO_LINT_COMMIT) \
 	&& go install -v github.com/golang/lint/golint
 
-# Configure the container for OSX cross compilation
-ENV OSX_SDK MacOSX10.11.sdk
-RUN set -x \
-	&& export OSXCROSS_PATH="/osxcross" \
-	&& git clone --depth 1 https://github.com/tpoechtrager/osxcross.git $OSXCROSS_PATH \
-	&& curl -sSL https://s3.dockerproject.org/darwin/${OSX_SDK}.tar.xz -o "${OSXCROSS_PATH}/tarballs/${OSX_SDK}.tar.xz" \
-	&& UNATTENDED=yes OSX_VERSION_MIN=10.6 ${OSXCROSS_PATH}/build.sh
-ENV PATH /osxcross/target/bin:$PATH
-
-# install seccomp
-# this can be changed to the ubuntu package libseccomp-dev if dockerinit is removed,
-# we need libseccomp.a (which the package does not provide) for dockerinit
-ENV SECCOMP_VERSION 2.2.3
-RUN set -x \
-	&& export SECCOMP_PATH="$(mktemp -d)" \
-	&& curl -fsSL "https://github.com/seccomp/libseccomp/releases/download/v${SECCOMP_VERSION}/libseccomp-${SECCOMP_VERSION}.tar.gz" \
-		| tar -xzC "$SECCOMP_PATH" --strip-components=1 \
-	&& ( \
-		cd "$SECCOMP_PATH" \
-		&& ./configure --prefix=/usr/local \
-		&& make \
-		&& make install \
-		&& ldconfig \
-	) \
-	&& rm -rf "$SECCOMP_PATH"
-
 # Install two versions of the registry. The first is an older version that
 # only supports schema1 manifests. The second is a newer version that supports
 # both. This allows integration-cli tests to cover push/pull with both schema1