Update rules_rust

Several changes I made in 971-Robot-Code first have been upstreamed,
including finished a few pieces that I now want to use.

Change-Id: Iac6317989c1d3a0c7886c7d4a5798c6dbcedf2a9
Signed-off-by: Brian Silverman <bsilver16384@gmail.com>
diff --git a/tools/lint/run-ci.sh b/tools/lint/run-ci.sh
index 5e48da6..33a3bf9 100755
--- a/tools/lint/run-ci.sh
+++ b/tools/lint/run-ci.sh
@@ -66,8 +66,8 @@
 
 cargo_raze() {
     local -r cargo_raze="$(readlink -f external/cargo_raze/impl/cargo_raze_bin)"
-    export CARGO="$(readlink -f external/rust/bin/cargo)"
-    export RUSTC="$(readlink -f external/rust/bin/rustc)"
+    export CARGO="$(readlink -f external/rust__x86_64-unknown-linux-gnu_tools/bin/cargo)"
+    export RUSTC="$(readlink -f external/rust__x86_64-unknown-linux-gnu_tools/bin/rustc)"
     cd "${BUILD_WORKSPACE_DIRECTORY}"
     # Note we don't run with --generate-lockfile here. If there's a new
     # dependency, we don't want to download it, just failing with an error