[llvm] [X86][NFC] Added/Updated SINCOS function testcases (PR #141283)

[Evgenii Kudriashov via llvm-commits]

e-kud wrote:

We also have `sincos.ll` that is for `Make sure this testcase codegens to the sin and cos instructions, not calls`. But it is not more the case because of ac217b7aa3987dc8a4952f213a57f985b5106bae. @topperc I wonder whether we want/need to keep it?

https://github.com/llvm/llvm-project/pull/141283