text: If/Elseif/Else
  -----
  <?php
  
  if      ($a) {}
  elseif  ($b) {}
  elseif  ($c) {}
  else         {}
  
  if ($a) {} // without else
  
  if      ($a):
  elseif  ($b):
  elseif  ($c):
  else        :
  endif;
  
  if ($a): endif; // without else
  -----
  array(
      0: Stmt_If(
          cond: Expr_Variable(
              name: a
          )
          stmts: array(
          )
          elseifs: array(
              0: Stmt_ElseIf(
                  cond: Expr_Variable(
                      name: b
                  )
                  stmts: array(
                  )
              )
              1: Stmt_ElseIf(
                  cond: Expr_Variable(
                      name: c
                  )
                  stmts: array(
                  )
              )
          )
          else: Stmt_Else(
              stmts: array(
              )
          )
      )
      1: Stmt_If(
          cond: Expr_Variable(
              name: a
          )
          stmts: array(
          )
          elseifs: array(
          )
          else: null
      )
      2: Stmt_If(
          cond: Expr_Variable(
              name: a
          )
          stmts: array(
          )
          elseifs: array(
              0: Stmt_ElseIf(
                  cond: Expr_Variable(
                      name: b
                  )
                  stmts: array(
                  )
              )
              1: Stmt_ElseIf(
                  cond: Expr_Variable(
                      name: c
                  )
                  stmts: array(
                  )
              )
          )
          else: Stmt_Else(
              stmts: array(
              )
          )
          comments: array(
              0: // without else
          )
      )
      3: Stmt_If(
          cond: Expr_Variable(
              name: a
          )
          stmts: array(
          )
          elseifs: array(
          )
          else: null
      )
      4: Stmt_Nop(
          comments: array(
              0: // without else
          )
      )
  )