[clang] [CIR] Upstream CmpOp (PR #133159)

[Andy Kaylor via cfe-commits]

================
@@ -710,6 +710,89 @@ class ScalarExprEmitter : public StmtVisitor<ScalarExprEmitter, mlir::Value> {
   HANDLEBINOP(Xor)
   HANDLEBINOP(Or)
 #undef HANDLEBINOP
+
+  mlir::Value emitCmp(const BinaryOperator *e) {
+    mlir::Value result;
+    QualType lhsTy = e->getLHS()->getType();
+    QualType rhsTy = e->getRHS()->getType();
+
+    auto clangCmpToCIRCmp =
+        [](clang::BinaryOperatorKind clangCmp) -> cir::CmpOpKind {
+      switch (clangCmp) {
+      case BO_LT:
+        return cir::CmpOpKind::lt;
+      case BO_GT:
+        return cir::CmpOpKind::gt;
+      case BO_LE:
+        return cir::CmpOpKind::le;
+      case BO_GE:
+        return cir::CmpOpKind::ge;
+      case BO_EQ:
+        return cir::CmpOpKind::eq;
+      case BO_NE:
+        return cir::CmpOpKind::ne;
+      default:
+        llvm_unreachable("unsupported comparison kind");
----------------
andykaylor wrote:

```suggestion
        llvm_unreachable("unsupported comparison kind for cir.cmp");
```

https://github.com/llvm/llvm-project/pull/133159