Mark Rust as not working with msan

Change-Id: I323ee4d2ac788de55fd8648d1c0a596f5ecc9931
Signed-off-by: Austin Schuh <austin.linux@gmail.com>
diff --git a/tools/BUILD b/tools/BUILD
index 8ea984a..5f26d54 100644
--- a/tools/BUILD
+++ b/tools/BUILD
@@ -82,6 +82,27 @@
     values = {"define": "have_ubsan=true"},
 )
 
+config_setting(
+    name = "has_msan",
+    values = {"define": "have_msan=true"},
+)
+
+config_setting(
+    name = "cpu_k8_msan",
+    constraint_values = ["@platforms//cpu:x86_64"],
+    values = {
+        "define": "have_msan=true",
+    },
+)
+
+config_setting(
+    name = "cpu_k8_no_msan",
+    constraint_values = ["@platforms//cpu:x86_64"],
+    flag_values = {
+        "@io_bazel_rules_go//go/config:msan": "false",
+    },
+)
+
 nodejs_binary(
     name = "tsc_wrapped_with_angular",
     data = [