[llvm] [Xtensa] Implement lowering SELECT_CC, SETCC. (PR #97017)

[Sergei Barannikov via llvm-commits]

================
@@ -33,7 +33,13 @@ enum {
   // Wraps a TargetGlobalAddress that should be loaded using PC-relative
   // accesses.  Operand 0 is the address.
   PCREL_WRAPPER,
-  RET
+  RET,
+
+  // Select with condition operator - This selects between a true value and
+  // a false value (ops #2 and #3) based on the boolean result of comparing
+  // the lhs and rhs (ops #0 and #1) of a conditional expression with the
+  // condition code in op #4
+  SELECT_CC
----------------
s-barannikov wrote:

```suggestion
  SELECT_CC,
```

https://github.com/llvm/llvm-project/pull/97017