Update benchmark allocations helper to support min count.

This is useful when we have many groups because each group
is a separate class.

Author: myronmarston

benchmarks/allocations/helper.rb

@@ -2,7 +2,7 @@
 require 'rspec/core'
 require 'allocation_stats'
 
-def benchmark_allocations(burn: 1)
+def benchmark_allocations(burn: 1, min_allocations: 0)
   stats = AllocationStats.new(burn: burn).trace do
     yield
   end
@@ -13,5 +13,11 @@ def benchmark_allocations(burn: 1)
               [:class_plus]
             end
 
-  puts stats.allocations(alias_paths: true).group_by(*columns).from_pwd.sort_by_size.to_text
+  results = stats.allocations(alias_paths: true).group_by(*columns).from_pwd.sort_by_size.to_text
+  filtered = results.split("\n").select do |line|
+    count = line[/\s+(\d+)\z/, 1]
+    count.nil? || Integer(count) >= min_allocations
+  end.join("\n")
+
+  puts filtered
 end