simplify: port PrimitiveBoxBool to C via SimplifyEnv (chunk 4)

First Category 2 handler using the C SimplifyEnv bridge.
simplify_primitive_box_bool_c uses simplify_env_emit_use_type +
simplify_env_emit_load_const to emit replacement instructions.
Validates the make_c_env/sync_c_env pattern for Env-using handlers.

Author: SonicField

Python/jit/hir/simplify.cpp

@@ -2801,8 +2801,12 @@ Register* simplifyInstr(Env& env, const Instr* instr) {
     case Opcode::kPrimitiveCompare:
       return simplifyPrimitiveCompare(
           env, static_cast<const PrimitiveCompare*>(instr));
-    case Opcode::kPrimitiveBoxBool:
-      return simplifyPrimitiveBoxBool(env, instr);
+    case Opcode::kPrimitiveBoxBool: {
+      SimplifyEnv cenv = make_c_env();
+      auto *r = static_cast<Register*>(simplify_primitive_box_bool_c(&cenv, instr));
+      sync_c_env(cenv);
+      return r;
+    }
     case Opcode::kIndexUnbox:
     case Opcode::kPrimitiveUnbox:
       return simplifyUnbox(env, instr);

Python/jit/hir/simplify_c.c

@@ -70,17 +70,15 @@ void *simplify_guard_type_identity_c(const void *instr) {
     return NULL;
 }
 
-/* ---- simplifyIsTruthy (partial — CBool constant folding) ----
- * If input is a known CBool constant, replace with the constant directly. */
-void *simplify_is_truthy_cbool_c(SimplifyEnv *env, const void *instr) {
+/* ---- simplifyPrimitiveBoxBool ----
+ * If input is a known int constant, replace with Py_True/Py_False. */
+void *simplify_primitive_box_bool_c(SimplifyEnv *env, const void *instr) {
     void *input = hir_c_get_operand(instr, 0);
     HirType input_type = hir_register_type(input);
-    HirType t_cbool = HIR_TYPE_CBOOL;
-    if (hir_type_is_subtype(input_type, t_cbool) &&
-        hir_type_has_int_spec(&input_type)) {
-        intptr_t val = hir_type_int_spec(&input_type);
-        PyObject *result = val ? Py_True : Py_False;
-        HirType result_type = hir_type_from_object(result);
+    if (hir_type_has_int_spec(&input_type)) {
+        simplify_env_emit_use_type(env, input, input_type);
+        PyObject *bool_obj = hir_type_int_spec(&input_type) ? Py_True : Py_False;
+        HirType result_type = hir_type_from_object(bool_obj);
         return simplify_env_emit_load_const(env, result_type);
     }
     return NULL;

Python/jit/hir/simplify_c.h

@@ -30,8 +30,8 @@ void *simplify_check_c(const void *instr);
 void *simplify_refine_type_c(const void *instr);
 void *simplify_guard_type_identity_c(const void *instr);
 
-/* Env-using handlers */
-void *simplify_is_truthy_cbool_c(SimplifyEnv *env, const void *instr);
+/* Env-using handlers (Category 2) */
+void *simplify_primitive_box_bool_c(SimplifyEnv *env, const void *instr);
 
 #ifdef __cplusplus
 }