anchor.diff:    llvm-polly = llvmPackages_latest.llvm-polly;
     clang-polly = llvmPackages_latest.clang.override { cc = llvmPackages_latest.clang-polly-unwrapped; };
   
  +  clang_9  = llvmPackages_9.clang;
     clang_8  = llvmPackages_8.clang;
     clang_7  = llvmPackages_7.clang;
     clang_6  = llvmPackages_6.clang;
  
positive.code:   lldb_6 = llvmPackages_6.lldb;
    lldb_7 = llvmPackages_7.lldb;
    lldb_8 = llvmPackages_8.lldb;
  
    llvm = llvmPackages.llvm;
    llvm-manpages = llvmPackages.llvm-manpages;
  
    llvm_8  = llvmPackages_8.llvm;
    llvm_7  = llvmPackages_7.llvm;
    llvm_6  = llvmPackages_6.llvm;
  
negative.code:   lld_6 = llvmPackages_6.lld;
    lld_7 = llvmPackages_7.lld;
    lld_8 = llvmPackages_8.lld;
    lld_9 = llvmPackages_9.lld;
  
    lldb = llvmPackages.lldb;
    lldb_4 = llvmPackages_4.lldb;
  