Update install.sh --fast and README (#924)

[ROCm/rccl commit: 3807c203fc]

projects/rccl/README.md

@@ -28,8 +28,9 @@ The root of this repository has a helper script 'install.sh' to build and instal
        --build_allreduce_only  Build only AllReduce + sum + float kernel
     -d|--dependencies          Install RCCL depdencencies
        --debug                 Build debug library
-       --disable_backtrace     Build without custom backtrace support
+       --enable_backtrace      Build with custom backtrace support
        --disable-colltrace     Build without collective trace
+       --disable-msccl-kernel  Build without MSCCL kernels
     -f|--fast                  Quick-build RCCL (local gpu arch only, no backtrace, and collective trace support)
     -h|--help                  Prints this help message
     -i|--install               Install RCCL library (see --prefix argument below)

projects/rccl/install.sh

@@ -87,10 +87,10 @@ while true; do
          --build_allreduce_only)     build_allreduce_only=true;                                                                        shift ;;
     -d | --dependencies)             install_dependencies=true;                                                                        shift ;;
          --debug)                    build_release=false;                                                                              shift ;;
-         --enable_backtrace)         build_bfd=true;                                                                                  shift ;;
+         --enable_backtrace)         build_bfd=true;                                                                                   shift ;;
          --disable-colltrace)        collective_trace=false;                                                                           shift ;;
          --disable-msccl-kernel)     msccl_kernel_enabled=false;                                                                       shift ;;
-    -f | --fast)                     build_bfd=false; build_local_gpu_only=true; collective_trace=false; msccl_kernel_enabled=false;   shift ;;
+    -f | --fast)                     build_local_gpu_only=true; collective_trace=false; msccl_kernel_enabled=false;                    shift ;;
     -h | --help)                     display_help;                                                                                     exit 0 ;;
     -i | --install)                  install_library=true;                                                                             shift ;;
     -j | --jobs)                     num_parallel_jobs=${2};                                                                           shift 2 ;;