move branch counter to branch instruction (from if) in preperation of while

lib/ast/if_expression.rb

@@ -1,21 +1,18 @@
 module Ast
   class IfExpression < Expression
 #    attr_reader  :cond, :if_true, :if_false
-    @@counter = 0   #naming the braches by counting mainly to get them back together in testing
     def compile frame , method
       is = cond.compile(frame , method)
       #      is.is_false(frame,method)
       # TODO should/will use different branches for different conditions. 
-      branch_name = "if_merge_#{@@counter}".to_sym
-      @@counter += 1
-      branch = Virtual::ImplicitBranch.new branch_name
+      branch = Virtual::ImplicitBranch.new "if_merge"
       method.add branch
       last = is
       if_true.each do |part|
         last = part.compile(frame,method )
         raise part.inspect if last.nil?
       end
-      merge = Virtual::Label.new(branch_name)
+      merge = Virtual::Label.new(branch.name)
       method.add merge
       branch.swap
       method.current = branch