Implement frozen modules (#4)

lib/micropython/gen-frozen.sh

+#!/bin/bash
+set -e
+
+PYTHON="$1"
+SOURCE_DIR="$2"
+OUTPUT="$3"
+QSTR_HEADER="$4"
+
+shift 4
+
+# We need the defs header, not the generated
+QSTR_HEADER="$(dirname "$QSTR_HEADER")/qstrdefs.preprocessed.h"
+
+"$PYTHON" "$SOURCE_DIR"/micropython/tools/mpy-tool.py \
+    --freeze \
+    --qstr-header "$QSTR_HEADER" \
+    -mlongint-impl longlong \
+    "$@" >"$OUTPUT"