Show number in error message even for one error

Co-authored-by: Adrian <[email protected]>

Author: Noratrieb

compiler/rustc_errors/src/lib.rs

@@ -1465,7 +1465,7 @@ impl HandlerInner {
         };
         let errors = match self.deduplicated_err_count {
             0 => Cow::from(""),
-            1 => Cow::from("aborting due to previous error"),
+            1 => Cow::from("aborting due to 1 previous error"),
             count => Cow::from(format!("aborting due to {count} previous errors")),
         };
         if self.treat_err_as_bug() {

compiler/rustc_hir_typeck/src/expr.rs

@@ -1936,7 +1936,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     /// 8 |     foo::Foo {};
     ///   |     ^^^^^^^^ missing `you_can_use_this_field`
     ///
-    /// error: aborting due to previous error
+    /// error: aborting due to 1 previous error
     /// ```
     fn report_missing_fields(
         &self,
@@ -2053,7 +2053,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     /// 8 |     foo::Foo {};
     ///   |     ^^^^^^^^
     ///
-    /// error: aborting due to previous error
+    /// error: aborting due to 1 previous error
     /// ```
     fn report_private_fields(
         &self,

library/core/src/intrinsics/mir.rs

@@ -193,7 +193,7 @@
 //! 27 | |     )
 //!    | |_____- binding declared here but left uninitialized
 //!
-//! error: aborting due to previous error
+//! error: aborting due to 1 previous error
 //!
 //! For more information about this error, try `rustc --explain E0381`.
 //! ```

tests/ui/associated-types/issue-36499.rs

@@ -1,4 +1,4 @@
-// error-pattern: aborting due to previous error
+// error-pattern: aborting due to 1 previous error
 
 fn main() {
     2 + +2;

tests/ui/parser/issues/issue-58094-missing-right-square-bracket.rs

@@ -1,5 +1,5 @@
 // Fixed in #66054.
 // ignore-tidy-trailing-newlines
 // error-pattern: this file contains an unclosed delimiter
-// error-pattern: aborting due to previous error
+// error-pattern: aborting due to 1 previous error
 #[Ѕ

tests/ui/parser/issues/issue-62524.rs

@@ -1,5 +1,5 @@
 // ignore-tidy-trailing-newlines
-// error-pattern: aborting due to previous error
+// error-pattern: aborting due to 1 previous error
 #![allow(uncommon_codepoints)]
 
 y![

tests/ui/parser/issues/issue-63135.rs

@@ -1,3 +1,3 @@
 // error-pattern: this file contains an unclosed delimiter
-// error-pattern: aborting due to previous error
+// error-pattern: aborting due to 1 previous error
 fn i(n{...,f #

tests/ui/parser/missing_right_paren.rs

@@ -1,4 +1,4 @@
 // ignore-tidy-trailing-newlines
 // error-pattern: this file contains an unclosed delimiter
-// error-pattern: aborting due to previous error
+// error-pattern: aborting due to 1 previous error
 fn main((ؼ