WindowsSupport.h is a public header, however if it gets included, will cause a compile error indicating that llvm/Config/config.h cannot be found, because config.h is a private header. However there is no actual dependency on the private things in this header, so it can be changed to the public config header.
Can you provide your preferred git author line in that case, i.e. Real Name <email@address>? (I'm sure I could dig up your signature somewhere too but asking in case you use multiple different ones) :-)