Ditto as #474 and #475: this time a single patch which fixes a reported preprocessor clash due to a redefinition of an already defined macro.
See https://github.com/GerHobbelt/sdcc/commits/fix-preproc-clash for the commit chain on-line: as this is a single patch the only relevant commit line there is the top one, obviously. :-)
HTH
Looks like this is in out fork of GCC cpp. Did upstream GCC fix this issue the same way? If yes, should we just rebase our fork to a newwer upstream GCC? @felixs?