ref: 1c90dd8f2c195e66a1ca9dadfd412a2ccc6dfb55 dir: /tests/cc/execute/0155-struct-compl.c/
extern struct X x; int foo(); int main() { extern struct X x; return &x != 0; } struct X {int v;}; int foo() { x.v = 0; return x.v; }