[CIR] Backport Comma Operator for ComplexType (#1822)

Backport the Comma Operator for ComplexType from the upstream

Author: AmrDeveloper

clang/lib/CIR/CodeGen/CIRGenExprComplex.cpp

@@ -317,7 +317,8 @@ class ComplexExprEmitter : public StmtVisitor<ComplexExprEmitter, mlir::Value> {
     return emitLoadOfLValue(LV, E->getExprLoc());
   };
   mlir::Value VisitBinComma(const BinaryOperator *E) {
-    llvm_unreachable("NYI");
+    CGF.emitIgnoredExpr(E->getLHS());
+    return Visit(E->getRHS());
   }
 
   mlir::Value

clang/test/CIR/CodeGen/complex.cpp

@@ -148,3 +148,19 @@ int _Complex complex_imag_operator_on_rvalue() {
 // LLVM: store { i32, i32 } zeroinitializer, ptr %[[RET_ADDR]], align 4
 // LLVM: %[[TMP_RET:.*]] = load { i32, i32 }, ptr %[[RET_ADDR]], align 4
 // LLVM: ret { i32, i32 } %[[TMP_RET]]
+
+void complex_comma_operator(int _Complex a, int _Complex b) {
+  int _Complex c = (a, b);
+}
+
+// CIR: %[[COMPLEX_A:.*]] = cir.alloca !cir.complex<!s32i>, !cir.ptr<!cir.complex<!s32i>>, ["a", init]
+// CIR: %[[COMPLEX_B:.*]] = cir.alloca !cir.complex<!s32i>, !cir.ptr<!cir.complex<!s32i>>, ["b", init]
+// CIR: %[[RESULT:.*]] = cir.alloca !cir.complex<!s32i>, !cir.ptr<!cir.complex<!s32i>>, ["c", init]
+// CIR: %[[TMP_B:.*]] = cir.load{{.*}} %[[COMPLEX_B]] : !cir.ptr<!cir.complex<!s32i>>, !cir.complex<!s32i>
+// CIR: cir.store{{.*}} %[[TMP_B]], %[[RESULT]] : !cir.complex<!s32i>, !cir.ptr<!cir.complex<!s32i>>
+
+// LLVM: %[[COMPLEX_A:.*]] = alloca { i32, i32 }, i64 1, align 4
+// LLVM: %[[COMPLEX_B:.*]] = alloca { i32, i32 }, i64 1, align 4
+// LLVM: %[[RESULT:.*]] = alloca { i32, i32 }, i64 1, align 4
+// LLVM: %[[TMP_B:.*]] = load { i32, i32 }, ptr %[[COMPLEX_B]], align 4
+// LLVM: store { i32, i32 } %[[TMP_B]], ptr %[[RESULT]], align 4