Description:

This PR fixes scope analysis edge cases in the React Compiler where var declarations and TypeScript constructs were incorrectly hoisted or leaked across scope boundaries.

Design Notes:

declare and global are TypeScript type-system annotations that don't affect runtime emission, yet they still create declarations that downstream code can reference. The analyzer must walk their bodies normally and create bindings accordingly, rather than skipping traversal.

Changes:

• Class static blocks as var boundaries
  var declarations inside static { } blocks are now scoped to the block itself, matching ECMAScript semantics, instead of leaking into the enclosing function.

• TypeScript namespace / module scopes
  namespace and module bodies now create proper TsModuleBlock scopes. Their members are no longer incorrectly hoisted to the Program scope.

• Consistent binding for declare enum
declare enum is now registered as a local binding so references resolve correctly.

• Refactoring
  Renamed enclosing_function_scope() → enclosing_var_scope() and updated ScopeFlags definitions to make scope-kind checks clearer.

Known Limitations:

TypeScript namespace merging is not yet supported. The scope collector treats each namespace/module declaration as an isolated lexical scope. Exported members in one block are not visible to later merged blocks, and they are modeled as plain local bindings. This is a similar issue described in #11607.

BREAKING CHANGE:

Related issue (if exists):

• feat(es/react-compiler): Add React Compiler #11917 (comment)