jak3: add missing files and implement pexcw (#3084)

Some files were in the `banned_objects` list and were thus excluded from
the `all_objs` file.

Also implements the `pexcw` instruction which is only used in `hfrag`
code.

decompiler/Disasm/InstructionDecode.cpp

@@ -556,8 +556,10 @@ static InstructionKind decode_mmi3(OpcodeFields fields) {
     case 0b11011:
       ASSERT(fields.rs() == 0);
       return IK::PCPYH;
+    case 0b11110:
+      return IK::PEXCW;
     default:
-      ASSERT(false);
+      ASSERT_MSG(false, fmt::format("unknown mmi3: 0b{:b}\n", fields.MMI_func()));
       return IK::UNKNOWN;
   }
 }