Store idents for `DefPathData` into crate metadata

Previously, we threw away the `Span` associated with a definition's
identifier when we encoded crate metadata, causing us to lose location
and hygiene information.

We now store the identifier's `Span` in the crate metadata.
When we decode items from the metadata, we combine
the name and span back into an `Ident`.

This improves the output of several tests, which previously had messages
suppressed due to dummy spans.

This is a prerequisite for #68686, since throwing away a `Span` means
that we lose hygiene information.

3 files changed, 18 insertions, 0 deletions

diff --git a/src/test/ui/error-codes/E0004-2.stderr b/src/test/ui/error-codes/E0004-2.stderr
index f5b41cd1cc0..8bf245648f8 100644
--- a/src/test/ui/error-codes/E0004-2.stderr
+++ b/src/test/ui/error-codes/E0004-2.stderr
@@ -3,6 +3,14 @@ error[E0004]: non-exhaustive patterns: `None` and `Some(_)` not covered
    |
 LL |     match x { }
    |           ^ patterns `None` and `Some(_)` not covered
+   | 
+  ::: $SRC_DIR/libcore/option.rs:LL:COL
+   |
+LL |     None,
+   |     ---- not covered
+...
+LL |     Some(#[stable(feature = "rust1", since = "1.0.0")] T),
+   |     ---- not covered
    |
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
diff --git a/src/test/ui/error-codes/E0005.stderr b/src/test/ui/error-codes/E0005.stderr
index 577c6e886d5..5028405e731 100644
--- a/src/test/ui/error-codes/E0005.stderr
+++ b/src/test/ui/error-codes/E0005.stderr
@@ -3,6 +3,11 @@ error[E0005]: refutable pattern in local binding: `None` not covered
    |
 LL |     let Some(y) = x;
    |         ^^^^^^^ pattern `None` not covered
+   | 
+  ::: $SRC_DIR/libcore/option.rs:LL:COL
+   |
+LL |     None,
+   |     ---- not covered
    |
    = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant
    = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html
diff --git a/src/test/ui/error-codes/E0297.stderr b/src/test/ui/error-codes/E0297.stderr
index f356a5b954d..e25fb09f157 100644
--- a/src/test/ui/error-codes/E0297.stderr
+++ b/src/test/ui/error-codes/E0297.stderr
@@ -3,6 +3,11 @@ error[E0005]: refutable pattern in `for` loop binding: `None` not covered
    |
 LL |     for Some(x) in xs {}
    |         ^^^^^^^ pattern `None` not covered
+   | 
+  ::: $SRC_DIR/libcore/option.rs:LL:COL
+   |
+LL |     None,
+   |     ---- not covered
 
 error: aborting due to previous error