[clang] [clang] Fix crashes when initializing constexpr int* with floating-point (PR #180376)

[Mariya Podchishchaeva via cfe-commits]

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@@ -8503,8 +8503,12 @@ ExprResult InitializationSequence::Perform(Sema &S,
         Expr::EvalResult ER;
         if (Entity.getType()->getAs<PointerType>() &&
             CurInit.get()->EvaluateAsRValue(ER, S.Context) &&
-            !ER.Val.isNullPointer()) {
+            // We continue and let it error later if Rvalue is not a pointer
+            ER.Val.isLValue() && 
+            !ER.Val.isNullPointer() &&
+            !ER.Val.getLValueBase().isNull()) {
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Fznamznon wrote:

Why do we need both checks? i.e. `ER.Val.isNullPointer()` AND `ER.Val.getLValueBase().isNull()`

https://github.com/llvm/llvm-project/pull/180376