[clang] [CIR] Upstream shift operators for VectorType (PR #139465)

[Andy Kaylor via cfe-commits]

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@@ -1401,18 +1401,19 @@ def ShiftOp : CIR_Op<"shift", [Pure]> {
     The `cir.shift` operation performs a bitwise shift, either to the left or to
     the right, based on the first operand. The second operand specifies the
     value to be shifted, and the third operand determines the number of
-    positions by which the shift is applied. Both the second and third operands
-    are required to be integers.
+    positions by which the shift is applied, they must be either all vector of
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andykaylor wrote:

```suggestion
    positions by which the shift is applied. They must be either all vector of
```

https://github.com/llvm/llvm-project/pull/139465