manually encode newlines on all printed commands

This way we group key value arguments: e.g.:

    make \
    -j 8 \
    all

instead of:

    make \
    -j \
    8 \
    all

and reach CLI nirvana, while also subtly breaking several commands due to
lack of testing.

run-toolchain

@@ -1,7 +1,6 @@
 #!/usr/bin/env python3
 
 import os
-import subprocess
 import sys
 
 import common
@@ -45,6 +44,7 @@ if args.dry:
     print(tool)
 else:
     sys.exit(common.run_cmd(
-        [tool] + args.extra_args,
+        [tool, common.Newline]
+        + common.add_newlines(args.extra_args),
         cmd_file=os.path.join(common.run_dir, 'run-toolchain.sh'),
     ))