[PATCH v4 7/8] perf hists browser: Add option for runtime switching perf data file

Based on perf report/top/scripts browser integration idea from acme. This will enable user to runtime switch the data file, when this option is selected, it will popup all the legal data files in current working directory, and the filename selected by user is saved in the global variable

[PATCH v4 7/8] perf hists browser: Add option for runtime switching perf data file

Based on perf report/top/scripts browser integration idea from acme. This will enable user to runtime switch the data file, when this option is selected, it will popup all the legal data files in current working directory, and the filename selected by user is saved in the global variable