[clang] [LifetimeSafety] Fix crash on ternary operator when one of the expressions is `throw` (PR #190345)

[via cfe-commits]

================
@@ -404,8 +408,18 @@ void FactsGenerator::VisitConditionalOperator(const ConditionalOperator *CO) {
   if (hasOrigins(CO)) {
     // Merge origins from both branches of the conditional operator.
     // We kill to clear the initial state and merge both origins into it.
-    killAndFlowOrigin(*CO, *CO->getTrueExpr());
-    flowOrigin(*CO, *CO->getFalseExpr());
+    const Expr *TrueExpr = CO->getTrueExpr();
+    const Expr *FalseExpr = CO->getFalseExpr();
+    bool Initialized = false;
+    for (const Expr *Branch : {TrueExpr, FalseExpr}) {
+      if (!producesConditionalResult(Branch))
+        continue;
+      if (!Initialized) {
+        killAndFlowOrigin(*CO, *Branch);
+        Initialized = true;
+      } else
+        flowOrigin(*CO, *Branch);
+    }
----------------
NeKon69 wrote:

To be honest I don't like this code myself, but I couldn't find a way to make it prettier

https://github.com/llvm/llvm-project/pull/190345