[clang] [CIR][AArch64] Implement vget_lane_bf16 and vgetq_lane_bf16 builtins (PR #186866)

[Andrzej Warzyński via cfe-commits]

================
@@ -34,3 +26,19 @@ bfloat16_t test_vduph_laneq_bf16(bfloat16x8_t v) {
   // LLVM: ret bfloat [[VGETQ_LANE]]
   return vduph_laneq_bf16(v, 7);
 }
+
----------------
banach-space wrote:

```suggestion
//===------------------------------------------------------===//
// 2.14.1.4 Split vectors
//===------------------------------------------------------===//

```

https://github.com/llvm/llvm-project/pull/186866