The files in the dmd subdirectory are part of the front-end for the
Digital Mars D compiler, hosted at https://github.com/dlang/dmd/.

They cover the lexical analysis, parsing, and semantic analysis of the
D Programming Language defined in the documents at https://dlang.org/.

To report a problem or look up known issues with the dmd front-end,
please visit the issue tracker at https://issues.dlang.org/.

All changes to dmd should go through the upstream repository first,
then merged back to GCC.