Use nproc instead of hardcoded 10 for build parallelism

src/ci/docker/host-x86_64/dist-x86_64-linux/build-binutils.sh

@@ -11,7 +11,7 @@ curl https://ftp.gnu.org/gnu/binutils/binutils-$VERSION.tar.bz2 | tar xfj -
 mkdir binutils-build
 cd binutils-build
 hide_output ../binutils-$VERSION/configure --prefix=/rustroot
-hide_output make -j10
+hide_output make -j$(nproc)
 hide_output make install
 
 cd ..

src/ci/docker/host-x86_64/dist-x86_64-linux/build-clang.sh

@@ -30,7 +30,7 @@ hide_output \
       -DLLVM_ENABLE_PROJECTS="clang;lld" \
       -DC_INCLUDE_DIRS="$INC"
 
-hide_output make -j10
+hide_output make -j$(nproc)
 hide_output make install
 
 cd ../..

src/ci/docker/host-x86_64/dist-x86_64-linux/build-cmake.sh

@@ -9,7 +9,7 @@ curl -L https://github.com/Kitware/CMake/releases/download/v$CMAKE/cmake-$CMAKE.
 mkdir cmake-build
 cd cmake-build
 hide_output ../cmake-$CMAKE/configure --prefix=/rustroot
-hide_output make -j10
+hide_output make -j$(nproc)
 hide_output make install
 
 cd ..

src/ci/docker/host-x86_64/dist-x86_64-linux/build-curl.sh

@@ -30,7 +30,7 @@ hide_output ../curl-$VERSION/configure \
       --disable-rtsp \
       --disable-ldaps \
       --disable-ldap
-hide_output make -j10
+hide_output make -j$(nproc)
 hide_output make install
 
 cd ..

src/ci/docker/host-x86_64/dist-x86_64-linux/build-gcc.sh

@@ -32,7 +32,7 @@ hide_output ../gcc-$GCC/configure \
     --prefix=/rustroot \
     --enable-languages=c,c++ \
     --disable-gnu-unique-object
-hide_output make -j10
+hide_output make -j$(nproc)
 hide_output make install
 ln -s gcc /rustroot/bin/cc
 

src/ci/docker/host-x86_64/dist-x86_64-linux/build-openssl.sh

@@ -14,7 +14,7 @@ curl $URL | tar xzf -
 
 cd openssl-$VERSION
 hide_output ./config --prefix=/rustroot shared -fPIC
-hide_output make -j10
+hide_output make -j$(nproc)
 hide_output make install
 cd ..
 rm -rf openssl-$VERSION

src/ci/docker/host-x86_64/dist-x86_64-linux/build-python.sh

@@ -14,7 +14,7 @@ cd python-build
 # than that fairly normal.
 CFLAGS='-I /rustroot/include' LDFLAGS='-L /rustroot/lib -L /rustroot/lib64' \
     hide_output ../Python-$VERSION/configure --prefix=/rustroot
-hide_output make -j10
+hide_output make -j$(nproc)
 hide_output make install
 
 cd ..