Add support for running tests in no_std mode.

cranelift/test-no_std.sh

@@ -0,0 +1,28 @@
+#!/bin/bash
+
+# This is the test script for testing the no_std configuration of
+# packages which support it.
+
+# Exit immediately on errors.
+set -e
+
+# Repository top-level directory.
+cd $(dirname "$0")
+topdir=$(pwd)
+
+function banner() {
+    echo "======  $@  ======"
+}
+
+# Test those packages which have no_std support.
+LIBS="cretonne frontend wasm native"
+cd "$topdir"
+for LIB in $LIBS
+do
+    banner "Rust unit tests in $LIB"
+    cd "lib/$LIB"
+    cargo test --features no_std
+    cd "$topdir"
+done
+
+banner "OK"