removed blocks and moved to labels

somewhat easier to understand the code as a linked list
relatively painless change, considering

lib/soml/compiler/while_statement.rb

@@ -6,25 +6,25 @@ module Soml
       branch_type , condition , statements = *statement
       condition = condition.first
 
-      # this is where the while ends and both branches meet
-      merge = @method.source.new_block("while merge")
-      # this comes after the current and beofre the merge
-      start = @method.source.new_block("while_start" )
-      @method.source.current start
+      add_code  start = Register::Label.new(statement , "while_start" )
 
-      cond = process(condition)
+      reset_regs
+      process(condition)
 
       branch_class = Object.const_get "Register::Is#{branch_type.capitalize}"
+      # this is where the while ends and both branches meet
+      merge = Register::Label.new(statement , "while_merge")
       add_code branch_class.new( condition , merge )
 
-      last = process_all(statements).last
+      reset_regs
+      process_all(statements)
 
       # unconditionally branch to the start
       add_code Register::Branch.new(statement,start)
 
       # continue execution / compiling at the merge block
-      @method.source.current merge
-      last
+      add_code merge
+      nil # statements don't return anything
     end
   end
 end