[llvm] [OCaml] Fix bindings after br -> uncondbr+condbr split (PR #186176)

[Alexis Engelke via llvm-commits]

================
@@ -180,8 +180,8 @@ module Opcode  = struct
   | Invalid (* not an instruction *)
   (* Terminator Instructions *)
   | Ret
-  | Br
   | Switch
+  | Invalid3
----------------
aengelke wrote:

Shouldn't switch and invalid be swapped? In the C API, LLVMRet is 1, 2 is unassigned, LLVMSwitch is 3.

https://github.com/llvm/llvm-project/pull/186176