add protoc_crosscompile_aarch64.sh (same as for java aarch64 tests)
diff --git a/kokoro/linux/aarch64/protoc_crosscompile_aarch64.sh b/kokoro/linux/aarch64/protoc_crosscompile_aarch64.sh
new file mode 100755
index 0000000..77942a4
--- /dev/null
+++ b/kokoro/linux/aarch64/protoc_crosscompile_aarch64.sh
@@ -0,0 +1,9 @@
+#!/bin/bash
+#
+# Builds protobuf C++ with aarch64 crosscompiler.
+
+set -ex
+
+./autogen.sh
+CXXFLAGS="-fPIC -g -O2" ./configure --host=aarch64
+make -j8