Remove conditional logic and consolidate NODE_FOR implementation to use
variable-sized nodes exclusively. This eliminates dual code paths and
completes the NODE_FOR migration.
Changes:
- inline new_for_var into new_for, remove p->var_nodes_enabled condition
- remove new_for_var function and forward declaration
- enhance gen_for_var with complete for-loop implementation from for_body
- remove codegen_for and for_body functions
- remove NODE_FOR case from main codegen switch (traditional cons-list path)
The for-loop implementation preserves Ruby's each-based semantics with
proper block scoping, argument handling, and loop control (break/next/redo)
while providing better memory efficiency through variable-sized nodes.
Co-authored-by: Claude <noreply@anthropic.com>
Yukihiro "Matz" Matsumoto
d45ec366c5