fix(c,cpp): a pointer, array or function member is not a supertype (#2394)

extractInheritance carried Go's struct-embedding check (a field_declaration
with no direct field_identifier names an embedded type) into every grammar
with a field_declaration_list. tree-sitter-c/cpp, and Objective-C's C
structs, nest a member's field_identifier inside its pointer/array/
function/reference declarator, so `SharedState* shared;`, `jv elements[];`
and `virtual Status Put(...) = 0;` all became `extends` edges to the
member's type: false supertypes in the type hierarchy, blast radius and
codegraph_explore, and false cpp-override call edges built on them
(google/leveldb: 246 of 302 extends edges).

Gate the branch to Go in the TS extractor, drop the mirrored arm from the
C/C++ kernel port (and the "kept for parity" quirk note), and drop the
inert copy from the Rust-language port. C++ base_class_clause, Objective-C
superclasses and Go embedding are unchanged.

Validated on leveldb, jq, llm.c and redis: every removed extends edge is a
member site, no base-clause edge is lost; gin, SDWebImage and ripgrep
dumps are byte-identical; kernel/wasm parity sweeps show 0 diffs.

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

docs/design/ccpp-kernel-port-checklist.md

@@ -194,7 +194,7 @@ function_declarator → null, 12-hop guard).
 | 4545 | local fn-ptr call fan-out (#932-adjacent) | bare-identifier callee found in cppLocalFnPtrs[callerId] → emit one `calls` ref PER recorded target, suppress the local name |
 | 5173 | stack construction (#1035) | cpp `declaration` where `type` ∈ {type_identifier, template_type, qualified_identifier} and any init_declarator has `value` ∈ {argument_list, initializer_list} → extractInstantiation |
 | 5183 | fn-ptr binding recording | inside a body: `declaration>init_declarator` (identifier declarator) or `assignment_expression` (identifier left); value must be pointer_expression whose child(0) is `&`; target ∈ {identifier, template_function, qualified_identifier}, template-stripped; per-callerId map of per-local Sets (branch reassignments accumulate) |
-| 5408 | base_class_clause → extends (#1043) | per base: type_identifier / qualified_identifier / template_type, stripCppTemplateArgs'd; access-specifier keywords skipped |
+| 5408 | base_class_clause → extends (#1043) | per base: type_identifier / qualified_identifier / template_type, stripCppTemplateArgs'd; access-specifier keywords skipped. The only c/cpp supertype source: the Go struct-embedding branch (`field_declaration` with no direct `field_identifier`) runs for Go only, so a pointer/array/reference/function member (`Cache* cache_;`) is never an `extends` |
 | 4740 | static member refs — **cpp only** (c not in STATIC_MEMBER_LANGS, line 345) | `Foo::BAR` value reads → `references` edge; VERIFY the MEMBER_ACCESS_TYPES shapes for qualified_identifier + the call-callee skip during the port |
 | — | value-reference edges | **c: YES** (VALUE_REF_LANGS line 401), **cpp: NO**. Port the value-ref machinery for C only (crib go.rs / tsjs — shadow prune, scope stack, MAX_VALUE_REF_NODES cap, CODEGRAPH_VALUE_REFS=0 kill) |
 | — | fn-ref capture (#756) | function-ref.ts:376: `c: cFamilySpec()`, `cpp: cFamilySpec({ addressOfOnly: true })`; note line ~582: `&Cls::m` exemption from the bare-ids-are-free-functions rule — read cFamilySpec fully when porting |

docs/design/rust-lang-kernel-port-checklist.md

@@ -317,10 +317,10 @@ trait_item — supertraits `trait Sub: Super + Display`). Per bound child:
 
 Each yields an `extends` ref from the trait node at the bound's position.
 Struct/enum extraction also calls extractInheritance; rust struct_item children
-include `field_declaration_list` → the 5652 recursion descends, but rust
-`field_declaration` always carries a `field_identifier` name so the Go
-struct-embedding branch (5496) never fires. Verify with the torture fixture
-anyway.
+include `field_declaration_list` → the 5652 recursion descends and finds
+nothing: the Go struct-embedding branch (5496) runs for Go only (it was inert
+here anyway — rust `field_declaration` always carries a `field_identifier`
+name), so rustlang.rs has no `field_declaration` arm.
 
 ### impl Trait for Type — extractRustImplItem (5690)