Bare own-name result of a VIRTUAL intrinsic-named method miscompiles

• Type: bug (codegen) — narrow
• Status: DONE (2026-06-26, commit on master)
• Owner: —
• Opened: 2026-06-24
• Found-by: TStream Read/Write methods (bug-read-write-reserved-as-method-names).

Symptom

Assigning a function's result by its OWN name, when (a) the name is an intrinsic keyword (Read/Write/Readln/Writeln) AND (b) the method is virtual, returns garbage:

function TStream.Read(var Buffer; Count: Integer): Integer; { virtual }
begin
  ...
  Read := Count;   { virtual + keyword name → caller gets garbage }
end;

Narrowing (all same body shape):

• Result := Count → correct (every layout, virtual or not).
• non-keyword name Rd := Count (virtual) → correct.
• keyword name, NON-virtual Read := Count → correct.
• keyword name + VIRTUAL Read := Count → garbage return (a code address).

The result var is always the Result slot (RetSymIdx), and the parser builds the same AN_ASSIGN(Result, expr) AST as the non-keyword path — yet codegen differs by (keyword-name AND virtual). Likely an own-name / VMT-recursion interaction in the virtual + intrinsic-name case (cf. the "mangling breaks FuncName-result/ recursion" landmine).

Current handling

Read := x (own-name result of an intrinsic-named method) is now a clear compile error directing to Result := ... — no silent miscompile. So this bug is latent behind that guard; Result := is the correct, robust form.

Done when

• Read := Count in a virtual intrinsic-named method returns the assigned value (remove the parser guard once codegen is correct).
• Regression test.

Resolution (2026-06-26, Track A)

The miscompile was resolved by intervening own-name/result fixes since the ticket opened. Removed the parser guard; the keyword-name branch now builds the same AN_ASSIGN(Result, expr) as the non-keyword own-name path (incl .field/[i]). Verified by test/test_virtual_keyword_result.pas (registered in make test): keyword-name virtual Read/Write result, override, and polymorphic dispatch all correct (5/6/10/10). Self-host byte-identical; make test green incl cross.