lowering: remove librustc dependency

Author: Centril

Cargo.lock

@@ -3479,7 +3479,6 @@ version = "0.0.0"
 dependencies = [
  "arena",
  "log",
- "rustc",
  "rustc_ast",
  "rustc_ast_pretty",
  "rustc_data_structures",

src/librustc_ast_lowering/Cargo.toml

@@ -12,7 +12,6 @@ doctest = false
 [dependencies]
 arena = { path = "../libarena" }
 log = { version = "0.4", features = ["release_max_level_info", "std"] }
-rustc = { path = "../librustc" }
 rustc_ast_pretty = { path = "../librustc_ast_pretty" }
 rustc_hir = { path = "../librustc_hir" }
 rustc_target = { path = "../librustc_target" }