Add a generous number of directories as buffer for forks and pre-existing differing behavior

Author: Jlalond

lldb/source/Plugins/ObjectFile/Minidump/MinidumpFileBuilder.cpp

@@ -75,6 +75,11 @@ Status MinidumpFileBuilder::AddHeaderAndCalculateDirectories() {
     }
   }
 
+  // Add a generous buffer of directories, these are quite small
+  // and forks may add new directories upstream LLDB hadn't accounted for
+  // when we started pre-calculating directory size, so this should account for that
+  m_expected_directories += 100;
+
   m_saved_data_size +=
       m_expected_directories * sizeof(llvm::minidump::Directory);
   Status error;