Add rustc-literal-escaper to allowed crates lists

Author: GuillaumeGomez

Diff for: src/tools/tidy/src/deps.rs

@@ -361,6 +361,7 @@ const PERMITTED_RUSTC_DEPENDENCIES: &[&str] = &[
     "regex-syntax",
     "rustc-demangle",
     "rustc-hash",
+    "rustc-literal-escaper",
     "rustc-rayon",
     "rustc-rayon-core",
     "rustc-stable-hash",
@@ -486,6 +487,7 @@ const PERMITTED_STDLIB_DEPENDENCIES: &[&str] = &[
     "rand_core",
     "rand_xorshift",
     "rustc-demangle",
+    "rustc-literal-escaper",
     "shlex",
     "syn",
     "unicode-ident",