This patch adds llvm.tan.* intrinsic and corresponding DAG nodes support
for X86 target.
The motivation of the patch is that even if it's uncommon to see tan in
real code, but it will make things a lot easier to do optimizations and
folds if we could have uniformity of trig intrinsics.
Related issue: https://github.com/llvm/llvm-project/issues/34950
Signed-off-by: Jun Zhang <firstname.lastname@example.org>