[llvm] [NewPM][CodeGen] add TargetPassConfig like API (PR #70906)

[Arthur Eubanks via llvm-commits]

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@@ -134,7 +167,19 @@ template <typename DerivedT> class CodeGenPassBuilder {
   }
 
   PassInstrumentationCallbacks *getPassInstrumentationCallbacks() const {
-    return PIC;
+    static PassInstrumentationCallbacks PseudoPIC;
+    return PIC ? PIC : &PseudoPIC;
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aeubanks wrote:

`PassBuilder` doesn't have a `static` `PIC` though. it's ok if it's `nullptr` since that's handled [here](https://github.com/llvm/llvm-project/blob/34a65980d7d2e1b05e3fc88535cafe606ee55e04/llvm/include/llvm/IR/PassInstrumentation.h#L230)

https://github.com/llvm/llvm-project/pull/70906