[llvm] [RemoveDIs][DebugInfo][NFC] Add Instruction and convenience functions to DPValue (PR #77896)

[Jeremy Morse via llvm-commits]

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@@ -41,6 +41,36 @@ DPValue::DPValue(Metadata *Location, DILocalVariable *DV, DIExpression *Expr,
 
 void DPValue::deleteInstr() { delete this; }
 
+DPValue *DPValue::createDPValue(Value *Location, DILocalVariable *DV,
+                                DIExpression *Expr, const DILocation *DI,
+                                Instruction *InsertBefore) {
+  auto *NewDPValue = new DPValue(ValueAsMetadata::get(Location), DV, Expr, DI,
+                                 LocationType::Value);
+  if (InsertBefore)
+    InsertBefore->getParent()->insertDPValueBefore(NewDPValue,
+                                                   InsertBefore->getIterator());
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jmorse wrote:

You miiiggghht be able to predeclare it as `SymbolTableList<Instruction, ilist_iterator_bits<true>>::iterator;` without needing a body definition for Instruction.

Removing and adding when necessary seems alright -- hopefully we can avoid it being necessary.

https://github.com/llvm/llvm-project/pull/77896