UPDATE - migrate linker.rs to new diagnostics infra

compiler/rustc_codegen_ssa/src/errors.rs

@@ -14,3 +14,45 @@ pub struct MissingNativeStaticLibrary<'a> {
 pub struct LibDefWriteFailure {
     pub error: Error,
 }
+
+#[derive(SessionDiagnostic)]
+#[diag(codegen_ssa::version_script_write_failure)]
+pub struct VersionScriptWriteFailure {
+    pub error: Error,
+}
+
+#[derive(SessionDiagnostic)]
+#[diag(codegen_ssa::symbol_file_write_failure)]
+pub struct SymbolFileWriteFailure {
+    pub error: Error,
+}
+
+#[derive(SessionDiagnostic)]
+#[diag(codegen_ssa::unsupported_arch)]
+pub struct UnsupportedArch;
+
+#[derive(SessionDiagnostic)]
+#[diag(codegen_ssa::msvc_path_not_found)]
+pub struct MsvcPathNotFound;
+
+#[derive(SessionDiagnostic)]
+#[diag(codegen_ssa::link_exe_not_found)]
+pub struct LinkExeNotFound;
+
+#[derive(SessionDiagnostic)]
+#[diag(codegen_ssa::ld64_unimplemented_modifier)]
+pub struct Ld64UnimplementedModifier;
+
+#[derive(SessionDiagnostic)]
+#[diag(codegen_ssa::linker_unsupported_modifier)]
+pub struct LinkerUnsupportedModifier;
+
+#[derive(SessionDiagnostic)]
+#[diag(codegen_ssa::L4Bender_exporting_symbols_unimplemented)]
+pub struct L4BenderExportingSymbolsUnimplemented;
+
+#[derive(SessionDiagnostic)]
+#[diag(codegen_ssa::no_natvis_directory)]
+pub struct NoNatvisDirectory {
+    pub error: Error,
+}