[llvm] [BOLT] Fix null pointer dereference in DWP processing with split DWARF (PR #191474)

[Farid Zakaria via llvm-commits]

================
@@ -665,8 +665,13 @@ void DWARFRewriter::updateDebugInfo() {
 
     updateUnitDebugInfo(SplitCU, DWODIEBuilder, DebugLocDWoWriter,
                         TempRangesSectionWriter, AddressWriter);
-    DebugLocDWoWriter.finalize(DWODIEBuilder,
-                               *DWODIEBuilder.getUnitDIEbyUnit(SplitCU));
+    DIE *UnitDIE = DWODIEBuilder.getUnitDIEbyUnit(SplitCU);
----------------
fzakaria wrote:

There are "corrupted" DWPs -- I think due to `--continue-on-cu-index-overflow` which we need to enable. I think effectively the offsets become invalid or becomes null.

https://github.com/llvm/llvm-project/pull/191474