Windows users must pass -pgml=gcc to ghc manually when compiling binaries with the Haskell Platform

[Ralith]

This occurs because the Haskell Platform links using the gcc (and MinGW) it ships with, causing the Haskell Platform libstdc++ to be linked, which is unlikely to be binary-compatible with a libstdc++ provided by a system MinGW as would typically be used to compile LLVM.