[CIR] Restore builtin switch-case order to match clang CodeGen (NFC) (#232635)
The builtin switch-case in CIRGenFunction::emitBuiltinExpr in CIR has
diverged from CodeGenFunction::EmitBuiltinExpr in OGCG w.r.t.
case-order.
Restore the order for consistency.
Assisted-by: Claude Opus 5.5
Signed-off-by: Steffen Holst Larsen <sholstla@amd.com>