add regex to rustc-workspace-hack

Author: RalfJung

Cargo.lock

@@ -3480,6 +3480,7 @@ dependencies = [
  "proc-macro2",
  "quote",
  "rand_core 0.5.1",
+ "regex",
  "serde",
  "serde_json",
  "smallvec",

src/tools/rustc-workspace-hack/Cargo.toml

@@ -79,6 +79,8 @@ crossbeam-utils = { version = "0.8.0", features = ["nightly"] }
 libc = { version = "0.2.79", features = ["align"] }
 # Ensure default features of libz-sys, which are disabled in some scenarios.
 libz-sys = { version = "1.1.2" }
+# same for regex
+regex = { version = "1.5.5" }
 proc-macro2 = { version = "1", features = ["default"] }
 quote = { version = "1", features = ["default"] }
 rand_core_0_5 = { package = "rand_core", version = "0.5.1", features = ["getrandom", "alloc", "std"] }