[llvm] 154331 build with c++23 on main (PR #154372)

[Alexandre Ganea via llvm-commits]

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@@ -10,9 +10,18 @@
 
 #include "llvm/DebugInfo/PDB/PDBSymDumper.h"
 
+namespace llvm {
+namespace pdb {
+
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aganea wrote:

You can also drop the extra lines here.

https://github.com/llvm/llvm-project/pull/154372