[CI] Update binutils for powerpc64 and powerpc64le

Cargo powerpc64 and powerpc64le are seeing `SIGILL` crashes in openssl,
which was found to be a linking problem, fixed by newer binutils. See
<rust-lang#57345 (comment)>

For powerpc64 we're using crosstool-ng, which doesn't offer a newer
binutils version, but we can just compile it separately. On powerpc64le
we're already building binutils. Both are now updated to binutils 2.32.

Closes rust-lang/cargo#6320
Closes rust-lang#57345
Closes rust-lang/rustup#1620

src/ci/docker/dist-powerpc64-linux/build-powerpc64-toolchain.sh

@@ -3,9 +3,28 @@ set -ex
 
 source shared.sh
 
+BINUTILS=2.32
+TARGET=powerpc64-unknown-linux-gnu
+PREFIX=/x-tools/$TARGET
+SYSROOT=$PREFIX/$TARGET/sysroot
+
 mkdir build
 cd build
 cp ../powerpc64-linux-gnu.config .config
 hide_output ct-ng build
 cd ..
 rm -rf build
+
+chmod -R u+w $PREFIX
+
+# Next, download and build newer binutils.
+mkdir binutils-$TARGET
+pushd binutils-$TARGET
+curl https://ftp.gnu.org/gnu/binutils/binutils-$BINUTILS.tar.bz2 | tar xjf -
+mkdir binutils-build
+cd binutils-build
+hide_output ../binutils-$BINUTILS/configure --target=$TARGET --prefix=$PREFIX --with-sysroot=$SYSROOT
+hide_output make -j10
+hide_output make install
+popd
+rm -rf binutils-$TARGET

src/ci/docker/dist-powerpc64le-linux/build-powerpc64le-toolchain.sh

@@ -4,7 +4,7 @@ set -ex
 
 source shared.sh
 
-BINUTILS=2.25.1
+BINUTILS=2.32
 GCC=5.3.0
 TARGET=powerpc64le-linux-gnu
 SYSROOT=/usr/local/$TARGET/sysroot