New Issue: problems with anonymous unnamed unions and LLVM compilation

17748, "mppf", "problems with anonymous unnamed unions and LLVM compilation", "2021-05-17T14:21:05Z"

Extern anonymous unnamed unions don't work with --llvm

Such a union is e.g.

typedef struct someStruct {
    // Anonymous union
    union {
        char alpha;
        int num;
    } u;
} someStruct;

Here the union members can be accessed with mySomeString.alpha etc.

Associated Future Test(s):
test/extern/unions/externAnonUnnamedUnionLLVM.chpl #17409