class Rcov::FileStatistics

Execution counts are just summated on a per-line basis.

* not covered (false) if it was uncovered in both
in either one
indicate that it was definitely executed, but it was inferred
* considered :inferred if the neither +self+ nor the +coverage+ array
+coverage+ array
* covered for sure (true) if it is covered in either +self+ or in the
As for code coverage, a line will be considered
Merge code coverage and execution count information.

def merge(lines, coverage, counts)
  coverage.each_with_index do |v, idx|
    case @coverage[idx]
    when :inferred 
      @coverage[idx] = v || @coverage[idx]
    when false 
      @coverage[idx] ||= v
    end
  end
  counts.each_with_index{|v, idx| @counts[idx] += v }
  precompute_coverage false
end