Minor optimization; emit proper unsupported messages for a couple of cases.

llvm-svn: 92153
diff --git a/clang/lib/CodeGen/CGExprAgg.cpp b/clang/lib/CodeGen/CGExprAgg.cpp
index 16249e4..b95fd79 100644
--- a/clang/lib/CodeGen/CGExprAgg.cpp
+++ b/clang/lib/CodeGen/CGExprAgg.cpp
@@ -396,12 +396,16 @@
 }
 
 void AggExprEmitter::VisitConditionalOperator(const ConditionalOperator *E) {
+  if (!E->getLHS()) {
+    CGF.ErrorUnsupported(E, "conditional operator with missing LHS");
+    return;
+  }
+
   llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true");
   llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false");
   llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end");
 
-  llvm::Value *Cond = CGF.EvaluateExprAsBool(E->getCond());
-  Builder.CreateCondBr(Cond, LHSBlock, RHSBlock);
+  CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock);
 
   CGF.StartConditionalBranch();
   CGF.EmitBlock(LHSBlock);