[llvm] [LLVM][IR] Add textual shorthand for specifying constant vector splats. (PR #74620)

[Nikita Popov via llvm-commits]

================
@@ -4299,6 +4299,11 @@ constants and smaller complex constants.
     "``< i32 42, i32 11, i32 74, i32 100 >``". Vector constants
     must have :ref:`vector type <t_vector>`, and the number and types of
     elements must match those specified by the type.
+
+    When creating a vector whose elements have the same constant value, the
+    prefered syntax is ``splat (<Ty> Val)``. For example: "``splat (i32 11)``".
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nikic wrote:

```suggestion
    preferred syntax is ``splat (<Ty> Val)``. For example: "``splat (i32 11)``".
```

https://github.com/llvm/llvm-project/pull/74620