Rust: some basic extraction of function names (with locations!)

rust/codegen/BUILD.bazel

@@ -0,0 +1,15 @@
+load("@bazel_skylib//rules:native_binary.bzl", "native_binary")
+
+native_binary(
+    name = "codegen",
+    src = "//misc/codegen",
+    out = "codegen",
+    args = [
+        "--configuration-file=$(location //rust:codegen.conf)",
+    ],
+    data = [
+        "//rust:codegen.conf",
+        "//rust:schema.py",
+    ],
+    visibility = ["//rust:__subpackages__"],
+)

rust/codegen/README.md

@@ -0,0 +1,6 @@
+This package aliases [`misc/codegen`](../misc/codegen) providing the Rust-specific options
+in [`rust/codegen.conf`](../codegen.conf).
+
+Running `bazel run //rust/codegen` will generate all checked in
+files ([dbscheme](../ql/lib/swift.dbscheme), [QL generated code](../ql/lib/codeql/swift/generated),
+[generated QL stubs](../ql/lib/codeql/swift/elements), [generated QL tests](../ql/test/extractor-tests/generated)).