Address PR comments. Remove redudant setConstexprUnknown and excess braces.

Author: shafik

clang/lib/AST/ExprConstant.cpp

@@ -1961,7 +1961,6 @@ CallStackFrame::createConstexprUnknownAPValues(const VarDecl *Key,
                                                APValue::LValueBase Base) {
   APValue &Result = ConstexprUnknownAPValues[MapKeyTy(Key, Base.getVersion())];
   Result = APValue(Base, CharUnits::One(), APValue::ConstexprUnknown{});
-  Result.setConstexprUnknown();
 
   return Result;
 }
@@ -3622,11 +3621,10 @@ static bool evaluateVarDeclInit(EvalInfo &Info, const Expr *E,
   // all subobjects includes the entire constant evaluation and whose dynamic
   // type is constexpr-unknown.
   if (AllowConstexprUnknown) {
-    if (!Result) {
+    if (!Result)
       Result = &Info.CurrentCall->createConstexprUnknownAPValues(VD, Base);
-    } else {
+    else
       Result->setConstexprUnknown();
-    }
   }
   return true;
 }