infra: add field accessors, hir_type_from_cdouble, container_eq gate

New instruction field accessors: hir_c_load_tuple_item_idx,
hir_c_load_field_offset, hir_c_load_array_item_offset.

hir_type_from_cdouble: C equivalent of Type::fromCDouble — constructs
CDouble HirType with double specialization.

container_eq: new wiring gate function exercising container equality
([1,2]==[1,2], dict, tuple). Catches type-dispatch bugs like the
TLongExact/TListExact confusion.

Author: SonicField

Python/jit/hir/hir_instr_c.h

@@ -764,6 +764,18 @@ static inline int32_t hir_c_load_arg_idx(const void *instr) {
     return ((const HirLoadArg *)instr)->arg_idx;
 }
 
+static inline size_t hir_c_load_tuple_item_idx(const void *instr) {
+    return ((const HirLoadTupleItem *)instr)->idx;
+}
+
+static inline intptr_t hir_c_load_field_offset(const void *instr) {
+    return (intptr_t)((const HirLoadField *)instr)->offset;
+}
+
+static inline intptr_t hir_c_load_array_item_offset(const void *instr) {
+    return ((const HirLoadArrayItem *)instr)->offset;
+}
+
 static inline HirType hir_c_load_arg_type(const void *instr) {
     return ((const HirLoadArg *)instr)->type;
 }

Python/jit/hir/hir_type_c.h

@@ -288,6 +288,15 @@ static inline int hir_type_has_value_spec(const HirType *t, HirType ty) {
            hir_type_is_subtype(*t, ty);
 }
 
+/* Construct a CDouble HirType with double specialization.
+ * C equivalent of Type::fromCDouble(d). */
+static inline HirType hir_type_from_cdouble(double d) {
+    HirType t = HIR_TYPE_CDOUBLE;
+    t.bits_and_flags |= ((uint64_t)HIR_SPEC_DOUBLE << HIR_TYPE_SPEC_SHIFT);
+    t.double_val = d;
+    return t;
+}
+
 /* Return the type with specialization stripped (spec_kind=Top, spec_val=0).
  * C equivalent of Type::unspecialized(). */
 static inline HirType hir_type_unspecialized(const HirType *t) {

scripts/gate_phoenix.sh

@@ -215,6 +215,9 @@ def make_closure(x):
         return x + y
     return inner
 
+def container_eq():
+    return ([1,2]==[1,2], [1,2]==[1,3], {1:2}=={1:2}, (1,2)==(1,2))
+
 tests = [
     (straight_add, (3, 4), 7),
     (recursive_fib, (10,), 55),
@@ -224,6 +227,7 @@ tests = [
     (multi_var, (10,), 230),
     (cond_loop, (10,), -5),
     (make_closure(10), (5,), 15),
+    (container_eq, (), (True, False, True, True)),
 ]
 for func, args, expected in tests:
     cinderjit.force_compile(func)