Add scripts for crosscompiling the toolchain using an already built native toolchain

build-cross-tools.sh

@@ -0,0 +1,21 @@
+#!/bin/sh
+
+set -e
+
+if [ $# -lt 3 ]; then
+    echo $0 native prefix arch
+    exit 1
+fi
+NATIVE="$1"
+PREFIX="$2"
+CROSS_ARCH="$3"
+
+export PATH=$NATIVE/bin:$PATH
+export EXEEXT=.exe
+export HOST=$CROSS_ARCH-w64-mingw32
+
+./build-llvm.sh $PREFIX
+./strip-llvm.sh $PREFIX
+./install-wrappers.sh $PREFIX
+./build-mingw-w64-widl.sh $PREFIX
+./prepare-cross-toolchain.sh $NATIVE $PREFIX $CROSS_ARCH