[Bug testsuite/65116] additional_sources not defined anymore during dg-final

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65116

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Is this related to these errors I'm seeing in the libstdc++ testsuite?

ERROR: 18_support/type_info/fundamental.cc: can't read "additional_sources": no
such variable for " dg-require-effective-target 2 dfp "

ERROR: 17_intro/shared_with_static_deps.cc: can't read "additional_sources": no
such variable for " dg-require-effective-target 4 fpic "

ERROR: 21_strings/c_strings/char/3_neg.cc: can't read "additional_sources": no
such variable for " dg-do 1 compile { target
correct_iso_cpp_string_wchar_protos } "

ERROR: 21_strings/c_strings/wchar_t/3_neg.cc: can't read
"et_cache(correct_iso_cpp_string_wchar_protos,value)": no such element in array
for " dg-do 1 compile { target correct_iso_cpp_string_wchar_protos } "

ERROR: 22_locale/collate/compare/wchar_t/wrapped_env.cc: can't read
"additional_sources": no such variable for " dg-require-iconv 4 "ISO8859-1" "

...