[llvm] [LV] Teach the loop vectorizer llvm.sincos is trivially vectorizable (PR #128035)

[Benjamin Maxwell via llvm-commits]

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@@ -0,0 +1,170 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --filter "(:|sincos|extractvalue|store)" --version 5
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MacDue wrote:

The `CHECK:` lines are automatically generated (without any manual edits) and still can be updated by the script without altering the `CHECK-COST:` lines (which are manual). 

This "NOTE:" line also includes the update script args `UTC_ARGS: --filter "(:|sincos|extractvalue|store)"` which means any future updates will be configured the same way. 

https://github.com/llvm/llvm-project/pull/128035