variations on parameter scoping

1 - case-one.js

var z = 'outer';
(function (
  x = (
    eval('var z = "param"; print("eval param1 :=", z)'),
    print('param1 :=', z)
  ),
  y = (
    eval('print("eval param2 :=", z)'),
    print('param2 :=', z)
  ),
) {
  var z;
  print('inner :=', z);
})();
print('outer :=', z);

2 - case-one-output.txt

#### ** CURRENT SPEC **, SpiderMonkey, V8, XS
eval param1 := param
param1 := param
eval param2 := outer
param2 := outer
inner := undefined
outer := outer

#### Chakra
eval param1 := param
param1 := outer
eval param2 := param
param2 := outer
inner := undefined
outer := outer

#### JavaScriptCore
eval param1 := param
param1 := param
eval param2 := param
param2 := param
inner := undefined
outer := param

#### ** PROPOSED SPEC **
eval param1 := param
param1 := param
eval param2 := param
param2 := param
inner := undefined
outer := outer

3 - case-two.js

// Note: differs from case one only in the removal of the `var z` in the function body
// The output only differs from case one for `inner :=`
var z = 'outer';
(function (
  x = (
    eval('var z = "param"; print("eval param1 :=", z)'),
    print('param1 :=', z)
  ),
  y = (
    eval('print("eval param2 :=", z)'),
    print('param2 :=', z)
  ),
) {
  print('inner :=', z);
})();
print('outer :=', z);

4 - case-two-output.txt

#### ** CURRENT SPEC **, SpiderMonkey, V8, XS
eval param1 := param
param1 := param
eval param2 := outer
param2 := outer
inner := outer
outer := outer

#### Chakra
eval param1 := param
param1 := outer
eval param2 := param
param2 := outer
inner := outer
outer := outer

#### JavaScriptCore
eval param1 := param
param1 := param
eval param2 := param
param2 := param
inner := param
outer := param

#### ** PROPOSED SPEC **
eval param1 := param
param1 := param
eval param2 := param
param2 := param
inner := param
outer := outer

5 - case-three.js

var z = 'outer';
(function (
  x = eval('var z = "param";'),
  z = 'default',
) {
  print('inner :=', z);
})();
print('outer :=', z);

6 - case-three-output.txt

#### ** CURRENT SPEC **, JavaScriptCore, SpiderMonkey, V8, XS
inner := default
outer := outer

#### ** PROPOSED SPEC **, Chakra
ReferenceError: Let/Const redeclaration

(Note: this is an error per the PR because of EvalDeclarationInstantiation 5.d.ii.2.a.i)

7 - strict mode.md

No changes would be made to the behavior of strict functions. var declarations in eval in strict mode do not get hoisted outside of the eval itself.