Remove the visit_lambda_var method from parser translator

Combine the translation logic for the visit_lambda_var method with the
visit_block_var method.

Author: egiurleo

lib/syntax_tree/translation/parser.rb

@@ -506,13 +506,13 @@ def visit_block_var(node)
             )
           end
 
-        params = node.params
         children =
-          if ::Parser::Builders::Default.emit_procarg0 && node.arg0?
+          if ::Parser::Builders::Default.emit_procarg0 && node.arg0? &&
+               node.pipe?
             # There is a special node type in the parser gem for when a single
             # required parameter to a block would potentially be expanded
             # automatically. We handle that case here.
-            required = params.requireds.first
+            required = node.params.requireds.first
             procarg0 =
               if ::Parser::Builders::Default.emit_arg_inside_procarg0 &&
                    required.is_a?(Ident)
@@ -537,18 +537,21 @@ def visit_block_var(node)
 
             [procarg0]
           else
-            visit(params).children
+            visit(node.params).children
           end
 
-        s(
-          :args,
-          children + shadowargs,
-          source_map_collection(
-            begin_token: source_range_length(node.location.start_char, 1),
-            end_token: source_range_length(node.location.end_char, -1),
-            expression: source_range_node(node)
-          )
-        )
+        location =
+          if node.location.start_char == node.location.end_char
+            source_map_collection(expression: nil)
+          else
+            source_map_collection(
+              begin_token: source_range_length(node.location.start_char, 1),
+              end_token: source_range_length(node.location.end_char, -1),
+              expression: source_range_node(node)
+            )
+          end
+
+        s(:args, children + shadowargs, location)
       end
 
       # Visit a BodyStmt node.
@@ -1541,7 +1544,7 @@ def visit_label(node)
 
       # Visit a Lambda node.
       def visit_lambda(node)
-        args = node.params.is_a?(LambdaVar) ? node.params : node.params.contents
+        args = node.params.is_a?(BlockVar) ? node.params : node.params.contents
         args_node = visit(args)
 
         type = :block
@@ -1589,34 +1592,6 @@ def visit_lambda(node)
         )
       end
 
-      # Visit a LambdaVar node.
-      def visit_lambda_var(node)
-        shadowargs =
-          node.locals.map do |local|
-            s(
-              :shadowarg,
-              [local.value.to_sym],
-              source_map_variable(
-                source_range_node(local),
-                source_range_node(local)
-              )
-            )
-          end
-
-        location =
-          if node.location.start_char == node.location.end_char
-            source_map_collection(expression: nil)
-          else
-            source_map_collection(
-              begin_token: source_range_length(node.location.start_char, 1),
-              end_token: source_range_length(node.location.end_char, -1),
-              expression: source_range_node(node)
-            )
-          end
-
-        s(:args, visit(node.params).children + shadowargs, location)
-      end
-
       # Visit an MAssign node.
       def visit_massign(node)
         s(