Add Trusty rules.mk file am: 8453e54e2e am: 0d2d5da6b8 am: 3c95e7e9a6

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/downcast-rs/+/2770001

Change-Id: I9065256a62af4a32f603cc34a6a701e92c513dd6
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
diff --git a/rules.mk b/rules.mk
new file mode 100644
index 0000000..7404137
--- /dev/null
+++ b/rules.mk
@@ -0,0 +1,15 @@
+# This file is generated by cargo2rulesmk.py --run.
+# Do not modify this file as changes will be overridden on upgrade.
+
+LOCAL_DIR := $(GET_LOCAL_DIR)
+MODULE := $(LOCAL_DIR)
+MODULE_CRATE_NAME := downcast_rs
+MODULE_SRCS := \
+	$(LOCAL_DIR)/src/lib.rs \
+
+MODULE_RUST_EDITION := 2015
+MODULE_RUSTFLAGS += \
+	--cfg 'feature="default"' \
+	--cfg 'feature="std"' \
+
+include make/library.mk