Modules are broken on contracts-main branch

[dascandy]

module.cppm:1:1: error: 'module;' introducing a global module fragment can appear only at the start of the translation unit
    1 | module;
      | ^~~~~~~
module.cppm:3:8: error: module declaration must occur at the start of the translation unit
    3 | export module mod;
      |        ^
module.cppm:1:1: note: add 'module;' to the start of the file to introduce a global module fragment
    1 | module;
      | ^

It smells like there is something being prepended to translation units, which breaks this handling. Reproducer is in #8 .