Early return if span is from expansion so we dont get empty span and ice later on

compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs

@@ -942,6 +942,11 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
             err.span_label(block.span, "this empty block is missing a tail expression");
             return;
         };
+        // FIXME expr and stmt have the same span if expr comes from expansion
+        // cc: https://github.com/rust-lang/rust/pull/147416#discussion_r2499407523
+        if stmt.span.from_expansion() {
+            return;
+        }
         let hir::StmtKind::Semi(tail_expr) = stmt.kind else {
             return;
         };

tests/ui/macros/macro-expansion-empty-span-147255.rs

@@ -0,0 +1,10 @@
+//! Regression test for <https://github.com/rust-lang/rust/issues/147255>
+
+fn main() {
+    let mut x = 4;
+    let x_str = {
+        format!("{}", x);
+        //()
+    };
+    println!("{}", x_str); //~ ERROR `()` doesn't implement `std::fmt::Display`
+}

tests/ui/macros/macro-expansion-empty-span-147255.stderr

@@ -0,0 +1,15 @@
+error[E0277]: `()` doesn't implement `std::fmt::Display`
+  --> $DIR/macro-expansion-empty-span-147255.rs:9:20
+   |
+LL |     println!("{}", x_str);
+   |               --   ^^^^^ `()` cannot be formatted with the default formatter
+   |               |
+   |               required by this formatting parameter
+   |
+   = help: the trait `std::fmt::Display` is not implemented for `()`
+   = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead
+   = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0277`.