[llvm] Reduce llvm-gsymutil memory usage (PR #91023)

[Greg Clayton via llvm-commits]

================
@@ -612,11 +617,16 @@ Error DwarfTransformer::convert(uint32_t NumThreads, OutputAggregator &Out) {
       DWARFDie Die = getDie(*CU);
       if (Die) {
         CUInfo CUI(DICtx, dyn_cast<DWARFCompileUnit>(CU.get()));
-        pool.async([this, CUI, &LogMutex, &Out, Die]() mutable {
+        pool.async([this, CUI, &CU, &LogMutex, &Out, Die]() mutable {
----------------
clayborg wrote:

If "CU" is a pointer, do we need to capture a reference? Could this just be:
```
pool.async([this, CUI, CU, &LogMutex, &Out, Die]() mutable {
```
Or does capture make `CU` into a `const *`?

https://github.com/llvm/llvm-project/pull/91023