[clang] [llvm] [HLSL] Implement the `degrees` intrinsic (PR #111209)

[Finn Plummer via cfe-commits]

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@@ -1643,6 +1646,23 @@ bool SPIRVInstructionSelector::selectLength(Register ResVReg,
       .constrainAllUses(TII, TRI, RBI);
 }
 
+bool SPIRVInstructionSelector::selectDegrees(Register ResVReg,
+                                             const SPIRVType *ResType,
+                                             MachineInstr &I) const {
+
+  assert(I.getNumOperands() == 3);
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inbelic wrote:

Correct, but I believe the first 2 operands of the spir-v instruction are usually used for the `ReturnType` and the `Result` register.

https://github.com/llvm/llvm-project/pull/111209