class Opal::Rewriters::BinaryOperatorAssignment

def self.new_temp 

def self.new_temp
  @@counter ||= 0
  @@counter += 1
  :"$binary_op_recvr_tmp_#{@@counter}"
end

def self.reset_tmp_counter! 

def self.reset_tmp_counter!
  @@counter = 0
end

def on_defined?(node)

to a static "assignment" string node
`defined?(a &&= 1)`
and
`defined?(a ||= 1)`
Rewrites any or_asgn and and_asgn node like 
def on_defined?(node)
  inner, _ = *node
  if inner.type == :op_asgn
    ASSIGNMENT_STRING_NODE
  else
    super(node)
  end
end

def on_op_asgn(node)

lhs += rhs 
def on_op_asgn(node)
  lhs, op, rhs = *node
  result = HANDLERS
           .fetch(lhs.type) { error "cannot handle LHS type: #{lhs.type}" }
           .call(node, lhs, op, rhs)
  process(result)
end