Auto merge of #43019 - kevinmehall:cleanup-errors, r=nikomatsakis

Remove unused code from librustc_errors

While extracting librustc_errors into a [reusable library](https://github.com/kevinmehall/codemap-diagnostic), I noticed some obsolete code that the `dead_code` warning missed because it was marked `pub` but not used elsewhere.

1 files changed, 0 insertions, 1 deletions

diff --git a/src/libsyntax/test.rs b/src/libsyntax/test.rs
index 86f5f42eac7..bd2c386cb8a 100644
--- a/src/libsyntax/test.rs
+++ b/src/libsyntax/test.rs
@@ -25,7 +25,6 @@ use std::rc::Rc;
 
 use codemap::{self, CodeMap, ExpnInfo, NameAndSpan, MacroAttribute, dummy_spanned};
 use errors;
-use errors::snippet::{SnippetData};
 use config;
 use entry::{self, EntryPointType};
 use ext::base::{ExtCtxt, Resolver};