Mark type fields as CT

Fixes #3276

src/ir.cpp

@@ -20405,6 +20405,7 @@ static Error ir_make_type_info_decls(IrAnalyze *ira, IrInstruction *source_instr
                         bigint_init_unsigned(&inner_fields[2].data.x_union.tag, 1);
 
                         ConstExprValue *payload = create_const_vals(1);
+                        payload->special = ConstValSpecialStatic;
                         payload->type = ira->codegen->builtin_types.entry_type;
                         payload->data.x_type = var->const_value->type;
 
@@ -20525,6 +20526,7 @@ static Error ir_make_type_info_decls(IrAnalyze *ira, IrInstruction *source_instr
                     bigint_init_unsigned(&inner_fields[2].data.x_union.tag, 0);
 
                     ConstExprValue *payload = create_const_vals(1);
+                    payload->special = ConstValSpecialStatic;
                     payload->type = ira->codegen->builtin_types.entry_type;
                     payload->data.x_type = type_entry;
 

test/stage1/behavior/type_info.zig

@@ -339,3 +339,10 @@ test "type info: extern fns with and without lib names" {
         }
     }
 }
+
+test "data field is a compile-time value" {
+    const S = struct {
+        const Bar = isize(-1);
+    };
+    comptime expect(@typeInfo(S).Struct.decls[0].data.Var == isize);
+}