Pass a Symbol to check_name, emit_feature_err, and related functions.

src/librustc_codegen_llvm/debuginfo/gdb.rs

@@ -9,6 +9,7 @@ use rustc::session::config::DebugInfo;
 use rustc_codegen_ssa::traits::*;
 
 use syntax::attr;
+use syntax::symbol::sym;
 
 
 /// Inserts a side-effect free instruction sequence that makes sure that the
@@ -66,8 +67,7 @@ pub fn get_or_insert_gdb_debug_scripts_section_global(cx: &CodegenCx<'ll, '_>)
 
 pub fn needs_gdb_debug_scripts_section(cx: &CodegenCx<'_, '_>) -> bool {
     let omit_gdb_pretty_printer_section =
-        attr::contains_name(&cx.tcx.hir().krate_attrs(),
-                            "omit_gdb_pretty_printer_section");
+        attr::contains_name(&cx.tcx.hir().krate_attrs(), sym::omit_gdb_pretty_printer_section);
 
     !omit_gdb_pretty_printer_section &&
     cx.sess().opts.debuginfo != DebugInfo::None &&