[IR] Move vector.insert/vector.extract out of experimental namespace

These intrinsics are now fundemental for SVE code generation and have been
present for a year and a half, hence move them out of the experimental
namespace.

Differential Revision: https://reviews.llvm.org/D127976
diff --git a/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp b/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
index 16d4094..41c7a8c 100644
--- a/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
@@ -652,8 +652,7 @@
     return None;
 
   auto *VecIns = dyn_cast<IntrinsicInst>(DupQLane->getArgOperand(0));
-  if (!VecIns ||
-      VecIns->getIntrinsicID() != Intrinsic::experimental_vector_insert)
+  if (!VecIns || VecIns->getIntrinsicID() != Intrinsic::vector_insert)
     return None;
 
   // Where the vector insert is a fixed constant vector insert into undef at