Port symbol_already_defined error

compiler/rustc_codegen_llvm/src/errors.rs

@@ -2,6 +2,7 @@ use rustc_errors::fluent;
 use rustc_errors::DiagnosticBuilder;
 use rustc_macros::SessionDiagnostic;
 use rustc_session::SessionDiagnostic;
+use rustc_span::Span;
 
 pub(crate) enum UnknownCTargetFeature<'a> {
     UnknownFeaturePrefix { feature: &'a str },
@@ -46,3 +47,11 @@ pub(crate) struct ErrorCreatingImportLibrary<'a> {
 #[derive(SessionDiagnostic)]
 #[diag(codegen_llvm::instrument_coverage_requires_llvm_12)]
 pub(crate) struct InstrumentCoverageRequiresLLVM12;
+
+#[derive(SessionDiagnostic)]
+#[diag(codegen_llvm::SymbolAlreadyDefined)]
+pub(crate) struct SymbolAlreadyDefined<'a> {
+    #[primary_span]
+    pub span: Span,
+    pub symbol_name: &'a str,
+}

compiler/rustc_codegen_llvm/src/mono_item.rs

@@ -25,10 +25,7 @@ impl<'tcx> PreDefineMethods<'tcx> for CodegenCx<'_, 'tcx> {
         let llty = self.layout_of(ty).llvm_type(self);
 
         let g = self.define_global(symbol_name, llty).unwrap_or_else(|| {
-            self.sess().span_fatal(
-                self.tcx.def_span(def_id),
-                &format!("symbol `{}` is already defined", symbol_name),
-            )
+            self.sess().emit_fatal(SymbolAlreadyDefined { span: self.tcx.def_span(def_id), symbol_name })
         });
 
         unsafe {