Set up to build Rust code with dependencies

cargo-raze is like gazelle, but for Rust code. It generates BUILD files
for external dependencies.

I'm putting this in a separate change from running it and setting up CI
to do that for ease of telling what's generated vs not.

Change-Id: I87a07255dca475514cae7bdbf9b0b62ce46e2512
Signed-off-by: Brian Silverman <bsilver16384@gmail.com>
diff --git a/tools/rust/BUILD b/tools/rust/BUILD
index e58bb19..fccc3e4 100644
--- a/tools/rust/BUILD
+++ b/tools/rust/BUILD
@@ -119,3 +119,16 @@
     toolchain = ":noop_rust_toolchain_impl",
     toolchain_type = "@rules_rust//rust:toolchain",
 )
+
+'''
+# TODO(Brian): Uncomment in the next change once dependencies exist.
+rust_binary(
+    name = "tweak_cargo_raze_output",
+    srcs = ["tweak_cargo_raze_output.rs"],
+    visibility = ["//visibility:public"],
+    deps = [
+        "//third_party/cargo:anyhow",
+        "//third_party/cargo:toml",
+    ],
+)
+'''