Adjust exportDynamic comment after change to allow STV_PROTECTED shared definition to set exportDynamic

[bd1976llvm]

Summary

Adjust comment to reflect change to allow STV_PROTECTED shared definitions to set exportDynamic.

[MaskRay]

LGTM.

[bd1976llvm]

Committed in https://github.com/llvm/llvm-project/commit/666aa43cbf829421b470c1ef6cf585d1dd3c94fd.

lld/ELF/Symbols.h

public:
   // NOTE: In Writer.cpp the field is used to mark local defined symbols
   // which are referenced by relocations when -r or --emit-relocs is given.
   uint8_t used : 1;
 
   // Used by a Defined symbol with protected or default visibility, to record
   // whether it is required to be exported into .dynsym. This is set when any of
   // the following conditions hold:
   //
-  // - If there is an interposable symbol from a DSO.
+  // - If there is an interposable symbol from a DSO. Note: We also do this for
+  //   STV_PROTECTED symbols which can't be interposed (to match BFD behavior).
   // - If -shared or --export-dynamic is specified, any symbol in an object
   //   file/bitcode sets this property, unless suppressed by LTO
   //   canBeOmittedFromSymbolTable().
   uint8_t exportDynamic : 1;
 
   // True if the symbol is in the --dynamic-list file. A Defined symbol with
   // protected or default visibility with this property is required to be
   // exported into .dynsym.