_Generic in C++ doesn't allow an elaborated type specifier as an association

[AaronBallman]

Clang supports _Generic as an extension in C++ mode, but the following C++ code doesn't parse when it should:

struct S {
  int i;
};

void func(struct S s) {
  (void)_Generic(s, struct S : 1); //  error: 'S' cannot be defined in a type specifier \
                                       error: expected class name \
                                       error: expected '{' after base class list
                                           
}

This use is not defining a new type specifier, it's attempting to use an elaborated type specifier for referencing the type.

[llvmbot]

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[llvmbot]

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