Remove deprecated MDModule bitcode support

Author: adrian-prantl

llvm/lib/Bitcode/Reader/MetadataLoader.cpp

@@ -1243,22 +1243,6 @@ Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata(
     if (Tag >= 1u << 16 || Version != 0)
       return error("Invalid record");
 
-    // Deprecated internal hack to support serializing MDModule.
-    // This node has since been deleted.
-    // Upgrading this node is not officially supported.  This code
-    // may be removed in the future.
-    if (Tag == dwarf::DW_TAG_module) {
-      if (Record.size() != 6)
-        return error("Invalid record");
-
-      MetadataList.assignValue(
-          GET_OR_DISTINCT(DIModule, (Context, getMDOrNull(Record[4]),
-                                     getMDString(Record[5]), nullptr, nullptr,
-                                     nullptr)),
-          NextMetadataNo++);
-      break;
-    }
-
     auto *Header = getMDString(Record[3]);
     SmallVector<Metadata *, 8> DwarfOps;
     for (unsigned I = 4, E = Record.size(); I != E; ++I)