feat: user type registry and enumerated types (CIE 4.1/4.2)

- TypeSystem: TypeKinds Enum/Record/Pointer with per-kind payloads and
  checked accessors; two-pass registration (names first, then definitions
  in source order) so pointer TYPEs may forward-reference; enum-constant
  table owned by TypeSystem so constants stay visible inside function
  bodies across the Symbols save/clear/restore. Dead surface removed
  (Custom kind, Printable/Builtin/ReferenceLike, ElementSize, hasType,
  CodeGen::getNamedValue/getLLVMType).
- Enums are i64 with 0-based ordinals (constexpr kEnumOrdinalBase); all
  type identity is by NAME. New emitCoercedExpr is the single admission
  gate, replacing raw coercion at assignments, array stores, BYVAL args,
  RETURN, IF/WHILE/REPEAT/FOR operands, file operands and builtin args;
  coerceValueToType now hard-errors if a user-kind target reaches it.
- Binary ops with user-kind operands are intercepted ahead of
  ArithmeticHandler ('&'-intercept precedent): same-enum comparisons,
  enum +/- INTEGER (with a runtime range check, [Fatal] on overflow, the
  only site that can manufacture an invalid ordinal), same-name pointer
  =/<>; everything else is a compile error naming the operator.
- OUTPUT is an exhaustive switch over TypeKind (enum prints its ordinal;
  record/pointer are compile errors, also covering whole-array OUTPUT);
  INPUT's silent %lld fallback for unknown kinds is now an explicit error.
- Enum value names are globally reserved: collisions with DECLARE,
  array names, parameters and function names are compile errors.
- RuntimeCheck: emitEnumRangeCheck + emitNullDerefCheck (used by the
  pointer phase) following the emitIndexCheck recipe.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

1 files changed, 12 insertions, 2 deletions

diff --git a/lib/CodeGen/ArrayHandler.cc b/lib/CodeGen/ArrayHandler.cc
index 7977563..d21d91c 100644
--- a/lib/CodeGen/ArrayHandler.cc
+++ b/lib/CodeGen/ArrayHandler.cc
@@ -84,6 +84,10 @@ void ArrayHandler::emitArrayDeclare(ArrayDeclareStmtAST *Stmt, CodeGen &CG) {
         CG.reportError("Unknown array element type %s", Stmt->getType().c_str());
         return;
     }
+    if (Types.lookupEnumConstant(Name)) {
+        CG.reportError("'%s' is an enum value and cannot be declared as an array", Name.c_str());
+        return;
+    }
 
     std::vector<Value*> Lows;
     std::vector<Value*> Highs;
@@ -199,8 +203,7 @@ void ArrayHandler::emitArrayAssign(ArrayAssignStmtAST *Stmt, CodeGen &CG) {
                                         Stmt->getLine(), CG, ElemTypeName);
     if (!ElemPtr) return;
 
-    Value *Val = CG.emitExpr(Stmt->getExpr());
-    Val = CG.coerceValueToType(Val, Types.resolve(ElemTypeName));
+    Value *Val = CG.emitCoercedExpr(Stmt->getExpr(), Types.resolve(ElemTypeName));
     if (!Val) return;
 
     Builder->CreateStore(Val, ElemPtr);
@@ -256,6 +259,13 @@ bool ArrayHandler::tryEmitArrayOutput(ExprAST *Expr, CodeGen &CG) {
         return false;
     }
 
+    const TypeInfo *ElemInfo = Types.resolve(getMetadata(Name)->ElementTypeName);
+    if (ElemInfo && !ElemInfo->isOutputtable()) {
+        CG.reportError("Cannot OUTPUT array %s of type %s; output individual fields",
+                       Name.c_str(), ElemInfo->Name.c_str());
+        return true; // diagnosed
+    }
+
     std::vector<Value*> Indices;
     if (IndexExprs && !emitCheckedIndices(Name, *IndexExprs, Line, false, CG, Indices)) {
         return true; // diagnosed