[llvm] [NewPM] Add port for aarch64-simd-scalar (PR #185256)

[Anshul Nigham via llvm-commits]

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@@ -62,9 +62,9 @@ STATISTIC(NumCopiesInserted, "Number of cross-class copies inserted");
 #define AARCH64_ADVSIMD_NAME "AdvSIMD Scalar Operation Optimization"
 
 namespace {
-class AArch64AdvSIMDScalar : public MachineFunctionPass {
-  MachineRegisterInfo *MRI;
-  const TargetInstrInfo *TII;
+class AArch64AdvSIMDScalarImpl {
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nigham wrote:

Couple of reasons why I added Impl:

- It's conventional in NewPM portings for codegen
- I'm hesitant to keep a class name the same while changing its type; may cause issues with anyone trying to use it as a library

https://github.com/llvm/llvm-project/pull/185256