[clang] [CIR][AArch64] add vshr_* builtins (PR #186693)

[Andrzej Warzyński via cfe-commits]

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@@ -17698,18 +17507,6 @@ uint64_t test_vshrd_n_u64_2() {
   return vshrd_n_u64(a, 64);
 }
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banach-space wrote:

Nice-to-have: Could you port this test as well?

https://github.com/llvm/llvm-project/pull/186693