Fix nested class scope index

[regularkevvv]

This Pull Request closes #4555.

How to reproduce:

// Class expression constructor with nested class
new (class{constructor(){class D{}}})();

// Static block with nested class
(class{static{class D{}}});

Both crash with: index out of bounds: the len is 0 but the index is 0

Additional patterns that trigger the bug:

// Constructor variants
[new (class{constructor(){class D{}}})()]
({x: new (class{constructor(){class D{}}})()})
new (class{ m(){} constructor(){class D{}} })()
new (class{ static m(){} constructor(){class D{}} })()
new (class{ get g(){return 1} constructor(){class D{}} })()
new (class{ #m(){} constructor(){class D{}} })()
new (class{ ['p']=1; constructor(){class D{}} })()

// Static block variants
(class{ static{let v=1} static{class D{}} })
(class{static{let v=1;((v)=>{class D{}})(v)}})

It changes the following:

• Fixed ScopeIndexVisitor::visit_class_expression_mut to call visit_function_like with force_function_scope: true for constructors, matching the behavior of visit_class_declaration_mut. Previously it called visit_function_expression_mut which passes false for force_function_scope.

• Fixed ScopeIndexVisitor::visit_class_element_mut for StaticBlock to pass true for force_function_scope. Previously it passed contains_direct_eval which is unrelated to whether a function scope is pushed at runtime.

Both class expression constructors and static blocks always have HAS_FUNCTION_SCOPE set during bytecode compilation, so the scope analyzer must account for this when assigning scope indices.

[github-actions]

Test262 conformance changes

Test result	main count	PR count	difference
Total	52,598	52,598	0
Passed	49,421	49,420	-1
Ignored	2,134	2,134	0
Failed	1,043	1,044	+1
Panics	0	0	0
Conformance	93.96%	93.96%	-0.00%

Broken tests (1):

test/staging/Temporal/v8/instant-to-json.js (previously Passed)

[codecov]

Codecov Report

❌ Patch coverage is 0% with 5 lines in your changes missing coverage. Please review.
✅ Project coverage is 56.50%. Comparing base (6ddc2b4) to head (b6fbad8).
⚠️ Report is 639 commits behind head on main.

Files with missing lines	Patch %	Lines
core/ast/src/scope_analyzer.rs	0.00%	5 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4592      +/-   ##
==========================================
+ Coverage   47.24%   56.50%   +9.25%     
==========================================
  Files         476      547      +71     
  Lines       46892    60060   +13168     
==========================================
+ Hits        22154    33935   +11781     
- Misses      24738    26125    +1387     

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