Add summarizeStats.py to tools directory

The summarizeStats.py script processes raw data provided by the
instrumented (stats-gathering) OpenMP* runtime library. It provides:

1) A radar chart which plots counters as frequency (per GigaTick) of use within
   the program. The frequencies are plotted as log10, however values less than
   one are kept as it is and represented in red color. This was done to help
   visualize the differences better.
2) Pie charts separating total time as compute and non-compute. The compute and
   non-compute times have their own pie charts showing the constructs that
   contributed to them. The percentages listed are with respect to the total
   time.
3) '.csv' file with percentage of time spent within the different constructs.

The script can be used as:
$ python $PATH_TO_SCRIPT/summarizeStats.py instrumented1.csv instrumented2.csv

Patch by Taru Doodi

Differential Revision: https://reviews.llvm.org/D41838

llvm-svn: 328568