Revert "Merge pull request #28029 from cstrahan/hardening-fix"

This reverts commit 0dbc006760, reversing
changes made to cb7f774265.

Should go into staging.

pkgs/build-support/cc-wrapper/add-flags.sh

@@ -30,10 +30,10 @@ fi
 # We need to mangle names for hygiene, but also take parameters/overrides
 # from the environment.
 for var in "${var_templates_list[@]}"; do
-    mangleVarList "$var" ${role_infixes[@]+"${role_infixes[@]}"}
+    mangleVarList "$var" "${role_infixes[@]}"
 done
 for var in "${var_templates_bool[@]}"; do
-    mangleVarBool "$var" ${role_infixes[@]+"${role_infixes[@]}"}
+    mangleVarBool "$var" "${role_infixes[@]}"
 done
 
 # `-B@out@/bin' forces cc to use ld-wrapper.sh when calling ld.