remove rustc_ast_pretty dep from rustc

Author: Centril

Cargo.lock

@@ -3093,7 +3093,6 @@ dependencies = [
  "rustc-rayon",
  "rustc-rayon-core",
  "rustc_apfloat",
- "rustc_ast_pretty",
  "rustc_attr",
  "rustc_data_structures",
  "rustc_errors",

src/librustc/Cargo.toml

@@ -21,8 +21,6 @@ rustc-rayon = "0.3.0"
 rustc-rayon-core = "0.3.0"
 polonius-engine = "0.11.0"
 rustc_apfloat = { path = "../librustc_apfloat" }
-# FIXME(Centril): remove this dependency when stuff is moved to rustc_lint.
-rustc_ast_pretty = { path = "../librustc_ast_pretty" }
 rustc_attr = { path = "../librustc_attr" }
 rustc_feature = { path = "../librustc_feature" }
 rustc_hir = { path = "../librustc_hir" }