When building aarch64-elf-gdb, include arm-eabi support.
diff --git a/doit b/doit
index 7aead53..813c091 100755
--- a/doit
+++ b/doit
@@ -229,10 +229,15 @@
     fi
 
     if [ ! -f $GDBBUILDPATH/built.txt ]; then
+        case "$TARGET" in
+            aarch64-elf) EXTRA_TARGETS="--enable-targets=arm-eabi" ;;
+            *) EXTRA_TARGETS="" ;;
+        esac
+
         echo building gdb
         mkdir -p $GDBBUILDPATH
         pushd $GDBBUILDPATH
-        log ../gdb-$GDBVER/configure --target=$TARGET --prefix=$INSTALLPATH --disable-werror
+        log ../gdb-$GDBVER/configure --target=$TARGET --prefix=$INSTALLPATH --disable-werror $EXTRA_TARGETS
         log make $PARALLEL
         log make install
         touch built.txt