[clang] [clang][CodeGen] Check initializer of zero-size fields for nullptr (PR #109271)

[Aaron Ballman via cfe-commits]

================
@@ -738,7 +738,7 @@ bool ConstStructBuilder::Build(const InitListExpr *ILE, bool AllowOverwrite) {
     // Zero-sized fields are not emitted, but their initializers may still
     // prevent emission of this struct as a constant.
     if (isEmptyFieldForLayout(CGM.getContext(), Field)) {
-      if (Init->HasSideEffects(CGM.getContext()))
+      if (Init && Init->HasSideEffects(CGM.getContext()))
----------------
AaronBallman wrote:

We should check GCC's behavior and follow their lead since it's a GNU extension, but my hope is that we can extend the logic for the GNU extension as well (I think it's more intuitive).

https://github.com/llvm/llvm-project/pull/109271