Add LLVM attributes in batches instead of individually

This should improve performance.

compiler/rustc_codegen_llvm/src/base.rs

@@ -95,7 +95,8 @@ pub fn compile_codegen_unit(tcx: TyCtxt<'_>, cgu_name: Symbol) -> (ModuleCodegen
             // If this codegen unit contains the main function, also create the
             // wrapper here
             if let Some(entry) = maybe_create_entry_wrapper::<Builder<'_, '_, '_>>(&cx) {
-                attributes::sanitize(&cx, SanitizerSet::empty(), entry);
+                let attrs = attributes::sanitize_attrs(&cx, SanitizerSet::empty());
+                attributes::apply_to_llfn(entry, llvm::AttributePlace::Function, &attrs);
             }
 
             // Run replace-all-uses-with for statics that need it