[llvm] Introduce DwarfUnit::addBlock helper method (PR #168446)

[Tom Tromey via llvm-commits]

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@@ -824,27 +832,14 @@ void DwarfUnit::constructTypeDIE(DIE &Buffer, const DIStringType *STy) {
     if (auto *VarDIE = getDIE(Var))
       addDIEEntry(Buffer, dwarf::DW_AT_string_length, *VarDIE);
   } else if (DIExpression *Expr = STy->getStringLengthExp()) {
-    DIELoc *Loc = new (DIEValueAllocator) DIELoc;
-    DIEDwarfExpression DwarfExpr(*Asm, getCU(), *Loc);
-    // This is to describe the memory location of the
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tromey wrote:

They didn't seem to add much value to me, so I removed them. In v2 of the patch I haven't touched this, but I'm happy to add them back if you want.

https://github.com/llvm/llvm-project/pull/168446