rustc_passes: Remove unused dependency rustc_trait_selection

Unused since commit 6a32e79
("stabilize union with 'ManuallyDrop' fields and 'impl Drop for Union'").

Author: joshtriplett

Cargo.lock

@@ -4211,7 +4211,6 @@ dependencies = [
  "rustc_session",
  "rustc_span",
  "rustc_target",
- "rustc_trait_selection",
  "tracing",
 ]
 

compiler/rustc_passes/Cargo.toml

@@ -17,6 +17,5 @@ rustc_target = { path = "../rustc_target" }
 rustc_ast = { path = "../rustc_ast" }
 rustc_serialize = { path = "../rustc_serialize" }
 rustc_span = { path = "../rustc_span" }
-rustc_trait_selection = { path = "../rustc_trait_selection" }
 rustc_lexer = { path = "../rustc_lexer" }
 rustc_ast_pretty = { path = "../rustc_ast_pretty" }