Revert of [strong] checking of this & super in constructors

src/messages.js

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // -------------------------------------------------------------------
 
 var kMessages = {
   // Error
   constructor_is_generator:      ["Class constructor may not be a generator"],
   constructor_is_accessor:       ["Class constructor may not be an accessor"],
@@ skipping 125 matching lines @@
   strong_switch_fallthrough :    ["In strong mode, switch fall-through is deprecated, terminate each case with 'break', 'continue', 'return' or 'throw'"],
   strong_equal:                  ["In strong mode, '==' and '!=' are deprecated, use '===' and '!==' instead"],
   strong_delete:                 ["In strong mode, 'delete' is deprecated, use maps or sets instead"],
   strong_var:                    ["In strong mode, 'var' is deprecated, use 'let' or 'const' instead"],
   strong_for_in:                 ["In strong mode, 'for'-'in' loops are deprecated, use 'for'-'of' instead"],
   strong_empty:                  ["In strong mode, empty sub-statements are deprecated, make them explicit with '{}' instead"],
   strong_use_before_declaration: ["In strong mode, declaring variable '", "%0", "' before its use is required"],
   strong_unbound_global:         ["In strong mode, using an undeclared global variable '", "%0", "' is not allowed"],
   strong_super_call_missing:     ["In strong mode, invoking the super constructor in a subclass is required"],
   strong_super_call_duplicate:   ["In strong mode, invoking the super constructor multiple times is deprecated"],
-  strong_super_call_misplaced:   ["In strong mode, the super constructor must be invoked before any assignment to 'this'"],
-  strong_constructor_super:      ["In strong mode, 'super' can only be used to invoke the super constructor, and cannot be nested inside another statement or expression"],
-  strong_constructor_this:       ["In strong mode, 'this' can only be used to initialize properties, and cannot be nested inside another statement or expression"],
+  strong_super_call_nested:      ["In strong mode, invoking the super constructor nested inside another statement or expression is deprecated"],
   strong_constructor_return_value: ["In strong mode, returning a value from a constructor is deprecated"],
-  strong_constructor_return_misplaced: ["In strong mode, returning from a constructor before its super constructor invocation or all assignments to 'this' is deprecated"],
+  strong_constructor_return_misplaced: ["In strong mode, returning from a constructor before its super constructor invocation is deprecated"],
   sloppy_lexical:                ["Block-scoped declarations (let, const, function, class) not yet supported outside strict mode"],
   malformed_arrow_function_parameter_list: ["Malformed arrow function parameter list"],
   cant_prevent_ext_external_array_elements: ["Cannot prevent extension of an object with external array elements"],
   redef_external_array_element:  ["Cannot redefine a property of an object with external array elements"],
   const_assign:                  ["Assignment to constant variable."],
   module_export_undefined:       ["Export '", "%0", "' is not defined in module"],
   duplicate_export:              ["Duplicate export of '", "%0", "'"],
   unexpected_super:              ["'super' keyword unexpected here"],
   extends_value_not_a_function:  ["Class extends value ", "%0", " is not a function or null"],
   prototype_parent_not_an_object: ["Class extends value does not have valid prototype property ", "%0"],
@@ skipping 1103 matching lines @@
 function SetUpStackOverflowBoilerplate() {
   var boilerplate = MakeRangeError(kStackOverflow);
 
   %DefineAccessorPropertyUnchecked(
       boilerplate, 'stack', StackTraceGetter, StackTraceSetter, DONT_ENUM);
 
   return boilerplate;
 }
 
 var kStackOverflowBoilerplate = SetUpStackOverflowBoilerplate();