Architecture phase A1.1b — mechanical storage relocation. Move the 9
declaration-fact maps out of the Lowering state bag into ProgramIndex:
high-fanout: fn_ast_map, foreign_class_map, global_names, type_alias_map
medium-fanout: struct_template_map, protocol_decl_map, protocol_ast_map,
module_const_map, ufcs_alias_map
168 self.<map> sites in lower.zig repointed to self.program_index.<map>;
external readers repointed too (core.zig foreign_class_map iteration;
lower.test.zig fn_ast_map / foreign_class_map). No duplicate storage, no
fallback path; zig build enforces no missed reference.
The four maps whose value types were Lowering-private pull those types into
program_index.zig as pub (GlobalInfo, StructTemplate + TemplateParam,
ProtocolDeclInfo + ProtocolMethodInfo, ModuleConstInfo); lower.zig aliases
them at file scope so call sites are unchanged.
Behavior is preserved exactly:
- per-map allocator unchanged — import_flags/fn_ast_map/global_names use the
lowering allocator (ProgramIndex.init), the other 7 keep their page_allocator
inline defaults;
- ProgramIndex.deinit frees only the 10 owned maps, never the borrowed
module_scopes / import_graph;
- TypeTable.aliases still borrows &self.program_index.type_alias_map, loaned at
lowerRoot with the same late-binding lifetime.
Extends program_index.test.zig with declaration-map round-trips (fn AST, type
alias, global, module const, foreign class, protocol decl/AST, struct template,
ufcs alias).
Registration logic (registerStructDecl / registerProtocolDecl /
registerForeignClassDecl, ...) stays in Lowering, writing through the index.
Gate green: zig build, zig build test, bash tests/run_examples.sh
(350 passed, 0 failed). lower.zig 19433 -> 19393 lines.