[clang] [CIR][AArch64] Upstream NEON shift left builtins (PR #186406)

[Andrzej Warzyński via cfe-commits]

================
@@ -936,3 +936,45 @@ uint32x4_t test_vabaq_u32(uint32x4_t v1, uint32x4_t v2, uint32x4_t v3) {
 // LLVM-NEXT:    ret <4 x i32> [[ADD_I]]
   return vabaq_u32(v1, v2, v3);
 }
+
----------------
banach-space wrote:

Section name to match https://arm-software.github.io/acle/neon_intrinsics/advsimd.html#set-all-lanes-to-the-same-value-2
```suggestion
//===------------------------------------------------------===//
// 2.1.3.1.1. Vector Shift Left
//===------------------------------------------------------===//
```

https://github.com/llvm/llvm-project/pull/186406