Backed out a functional refactoring.

upb/encode.c

@@ -448,17 +448,11 @@ static bool encode_shouldencode(upb_encstate* e, const upb_Message* msg,
         memcpy(&ch, mem, 1);
         return ch != 0;
       }
-#if UINTPTR_MAX == 0xffffffff
-      case upb_FieldRep_Pointer:
-#endif
       case kUpb_FieldRep_4Byte: {
         uint32_t u32;
         memcpy(&u32, mem, 4);
         return u32 != 0;
       }
-#if UINTPTR_MAX != 0xffffffff
-      case kUpb_FieldRep_Pointer:
-#endif
       case kUpb_FieldRep_8Byte: {
         uint64_t u64;
         memcpy(&u64, mem, 8);

upb/msg_internal.h

@@ -97,10 +97,17 @@ typedef enum {
 typedef enum {
   kUpb_FieldRep_1Byte = 0,
   kUpb_FieldRep_4Byte = 1,
-  kUpb_FieldRep_Pointer = 2,
+  kUpb_FieldRep_8Byte = 2,
   kUpb_FieldRep_StringView = 3,
-  kUpb_FieldRep_8Byte = 4,
+
-  kUpb_FieldRep_Shift = 5,  // Bit offset of the rep in upb_MiniTable_Field.mode
+#if UINTPTR_MAX == 0xffffffff
+  kUpb_FieldRep_Pointer = kUpb_FieldRep_4Byte,
+#else
+  kUpb_FieldRep_Pointer = kUpb_FieldRep_8Byte,
+#endif
+
+  kUpb_FieldRep_Shift =
+      6, /* Bit offset of the rep in upb_MiniTable_Field.mode */
 } upb_FieldRep;
 
 UPB_INLINE upb_FieldMode upb_FieldMode_Get(const upb_MiniTable_Field* field) {