Revert "Factor formal argument parsing into ParserBase"

src/messages.js

Index: src/messages.js
diff --git a/src/messages.js b/src/messages.js
index a0f366b10b2f36d850fe900504ae29020ad82a34..2ade557aa2ca75e1e22ec2c9c68cf03f8e8ce6fb 100644
--- a/src/messages.js
+++ b/src/messages.js
@@ -201,11 +201,7 @@ var kMessages = {
   array_not_subclassable:        ["Subclassing Arrays is not currently supported."],
   for_in_loop_initializer:       ["for-in loop variable declaration may not have an initializer."],
   for_of_loop_initializer:       ["for-of loop variable declaration may not have an initializer."],
-  for_inof_loop_multi_bindings:  ["Invalid left-hand side in ", "%0", " loop: Must have a single binding."],
-  bad_getter_arity:              ["Getter must not have any formal parameters."],
-  bad_setter_arity:              ["Setter must have exactly one formal parameter."],
-  this_formal_parameter:         ["'this' is not a valid formal parameter name"],
-  duplicate_arrow_function_formal_parameter: ["Arrow function may not have duplicate parameter names"]
+  for_inof_loop_multi_bindings:  ["Invalid left-hand side in ", "%0", " loop: Must have a single binding."]
 };