Add docker configurations used by the buildbots.

These are the scripts I use to create the docker images for
the build bots and run them.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@347244 91177308-0d34-0410-b5e6-96231b3b80d8

utils/docker/scripts/build_gcc.sh

@@ -0,0 +1,91 @@
+#!/usr/bin/env bash
+#===- libcxx/utils/docker/scripts/build-gcc.sh ----------------------------===//
+#
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+#
+#===-----------------------------------------------------------------------===//
+
+set -e
+
+
+function show_usage() {
+  cat << EOF
+Usage: build-gcc.sh [options]
+
+Run autoconf with the specified arguments. Used inside docker container.
+
+Available options:
+  -h|--help           show this help message
+  --source            the source path from which to run the configuration.
+  --to                destination directory where to install the targets.
+Required options: --to, at least one --install-target.
+
+All options after '--' are passed to CMake invocation.
+EOF
+}
+
+GCC_INSTALL_DIR=""
+GCC_SOURCE_DIR=""
+
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+    --to)
+      shift
+      GCC_INSTALL_DIR="$1"
+      shift
+      ;;
+    --source)
+      shift
+      GCC_SOURCE_DIR="$1"
+      shift
+      ;;
+    -h|--help)
+      show_usage
+      exit 0
+      ;;
+    *)
+      echo "Unknown option: $1"
+      exit 1
+  esac
+done
+
+if [ "$GCC_INSTALL_DIR" == "" ]; then
+  echo "No install directory. Please specify the --to argument."
+  exit 1
+fi
+
+if [ "$GCC_SOURCE_DIR" == "" ]; then
+  echo "No source directory. Please specify the --source argument."
+  exit 1
+fi
+
+GCC_NAME=`basename $GCC_SOURCE_DIR`
+GCC_BUILD_DIR="/tmp/gcc-build-root/build-$GCC_NAME"
+
+mkdir -p "$GCC_INSTALL_DIR"
+mkdir -p "$GCC_BUILD_DIR"
+pushd "$GCC_BUILD_DIR"
+
+# Run the build as specified in the build arguments.
+echo "Running configuration"
+$GCC_SOURCE_DIR/configure --prefix=$GCC_INSTALL_DIR \
+  --disable-bootstrap --disable-libgomp --disable-libitm \
+  --disable-libvtv --disable-libcilkrts --disable-libmpx \
+  --disable-liboffloadmic --disable-libcc1 --enable-languages=c,c++
+
+NPROC=`nproc`
+echo "Running build with $NPROC threads"
+make -j$NPROC
+
+echo "Installing to $GCC_INSTALL_DIR"
+make install -j$NPROC
+
+popd
+
+# Cleanup.
+rm -rf "$GCC_BUILD_DIR"
+
+echo "Done"