Rust: Enable LTO for the extractor

misc/bazel/rust.bzl

@@ -1,17 +1,41 @@
 load("@rules_rust//rust:defs.bzl", "rust_binary")
 load("@semmle_code//buildutils-internal:glibc_symbols_check.bzl", "glibc_symbols_check")
 load("@semmle_code//buildutils-internal:lipo.bzl", "universal_binary")
+load("@semmle_code//buildutils-internal:transitions.bzl", "forward_binary_from_transition", "get_transition_attrs")
+
+def _full_lto_transition_impl(_settings, _attr):
+    return {"@rules_rust//rust/settings:lto": "fat"}
+
+_full_lto_transition = transition(
+    implementation = _full_lto_transition_impl,
+    inputs = [],
+    outputs = ["@rules_rust//rust/settings:lto"],
+)
+
+_full_lto_binary = rule(
+    implementation = forward_binary_from_transition,
+    attrs = get_transition_attrs(_full_lto_transition),
+)
 
 def codeql_rust_binary(
         name,
+        full_lto = False,
         target_compatible_with = None,
         visibility = None,
         symbols_test = True,
         **kwargs):
     rust_label_name = "single_arch/" + name
+    binary_dep = ":" + rust_label_name
+    if full_lto:
+        lto_label_name = "full_lto/" + name
+        _full_lto_binary(
+            name = lto_label_name,
+            dep = binary_dep,
+        )
+        binary_dep = ":" + lto_label_name
     universal_binary(
         name = name,
-        dep = ":" + rust_label_name,
+        dep = binary_dep,
         target_compatible_with = target_compatible_with,
         visibility = visibility,
     )

rust/extractor/BUILD.bazel

@@ -11,6 +11,7 @@ codeql_rust_binary(
         "src/qltest_cargo.mustache",
         "src/nightly-toolchain/rust-toolchain.toml",
     ],
+    full_lto = True,
     proc_macro_deps = all_crate_deps(
         proc_macro = True,
     ) + [