[llvm] [RISCV][llvm] Handle `ptr` element type in `lowerDeinterleaveIntrinsicToLoad` and `lowerInterleaveIntrinsicToStore` (PR #107079)

[Luke Lau via llvm-commits]

================
@@ -21951,7 +21951,9 @@ bool RISCVTargetLowering::lowerDeinterleaveIntrinsicToLoad(
         Intrinsic::riscv_vlseg6, Intrinsic::riscv_vlseg7,
         Intrinsic::riscv_vlseg8};
 
-    unsigned SEW = ResVTy->getElementType()->getScalarSizeInBits();
+    unsigned SEW = ResVTy->getElementType()->isPointerTy()
+                       ? Subtarget.getXLen()
+                       : ResVTy->getElementType()->getScalarSizeInBits();
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lukel97 wrote:

Can we use DataLayout instead of hardcoding XLEN?
```suggestion
unsigned SEW = DI->getDataLayout().getTypeSizeInBits(ResVTy->getElementType());
```

https://github.com/llvm/llvm-project/pull/107079