re PR go/77625 (go/gofrontend/ast-dump.cc:169:42: error: ‘new’ of type ‘std::ofstr eam {aka std::basic_ofstream<char>}’ with extended alignment 16)

	PR go/77625

    compiler: allocate std::ofstream as a local variable
    
    GCC PR 77625 points out a warning about new std::ofstream.  I don't know
    how that is supposed to work, but in this case the std::ofstream may as
    well be a local variable anyhow.
    
    Reviewed-on: https://go-review.googlesource.com/29435

From-SVN: r240279