[clang] [clang] Remove separate evaluation step for static class member init. (PR #142713)

[Eli Friedman via cfe-commits]

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@@ -143,3 +143,8 @@ namespace fold_initializer {
   const float A::f = __builtin_is_constant_evaluated();
   static_assert(fold(A::f == 1.0f));
 }
+
+struct GH99680 {
+  static const int x = 1/(1-__builtin_is_constant_evaluated()); // expected-error {{in-class initializer for static data member is not a constant expression}} \
+    // expected-note {{division by zero}}
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efriedma-quic wrote:

This example is illegal for the same reason you can't write `int f(); struct X { static const int x = f(); };`.  Normally static data members aren't allowed to have initializers at all if they're not `inline`.  But there's a very narrow carveout in [class.static.data]p4: if the type is a `const` non-`volatile` integer type, it's allowed if the initializer is constant expression.

https://github.com/llvm/llvm-project/pull/142713