Avoid ICE of attempt to add with overflow in emitter

compiler/rustc_errors/src/lib.rs

@@ -331,7 +331,7 @@ impl CodeSuggestion {
                     });
                     buf.push_str(&part.snippet);
                     let cur_hi = sm.lookup_char_pos(part.span.hi());
-                    if cur_hi.line == cur_lo.line {
+                    if cur_hi.line == cur_lo.line && !part.snippet.is_empty() {
                         // Account for the difference between the width of the current code and the
                         // snippet being suggested, so that the *later* suggestions are correctly
                         // aligned on the screen.

tests/ui/suggestions/issue-109396.rs

@@ -0,0 +1,12 @@
+fn main() {
+    {
+        let mut mutex = std::mem::zeroed(
+            //~^ ERROR this function takes 0 arguments but 4 arguments were supplied
+            file.as_raw_fd(),
+            //~^ ERROR expected value, found macro `file`
+            0,
+            0,
+            0,
+        );
+    }
+}

tests/ui/suggestions/issue-109396.stderr

@@ -0,0 +1,34 @@
+error[E0423]: expected value, found macro `file`
+  --> $DIR/issue-109396.rs:5:13
+   |
+LL |             file.as_raw_fd(),
+   |             ^^^^ not a value
+
+error[E0061]: this function takes 0 arguments but 4 arguments were supplied
+  --> $DIR/issue-109396.rs:3:25
+   |
+LL |         let mut mutex = std::mem::zeroed(
+   |                         ^^^^^^^^^^^^^^^^
+LL |
+LL |             file.as_raw_fd(),
+   |             ---------------- unexpected argument
+LL |
+LL |             0,
+   |             - unexpected argument of type `{integer}`
+LL |             0,
+   |             - unexpected argument of type `{integer}`
+LL |             0,
+   |             - unexpected argument of type `{integer}`
+   |
+note: function defined here
+  --> $SRC_DIR/core/src/mem/mod.rs:LL:COL
+help: remove the extra arguments
+   |
+LL -             file.as_raw_fd(),
+LL +             ,
+   |
+
+error: aborting due to 2 previous errors
+
+Some errors have detailed explanations: E0061, E0423.
+For more information about an error, try `rustc --explain E0061`.