Having bootstrap-ubsan, one can see:

$ cat /tmp/ubsan.i
int d();
int e();

__attribute__((__cold__)) int a();
int b() { a(); }
int c() {
  b();
  if (d())
    e();
}

$ gcc -O2 /tmp/ubsan.i -c
../../gcc/profile-count.h:190:14: runtime error: signed integer overflow: 1073741823 * 10000 cannot be represented in type 'int'
../../gcc/profile-count.h:190:14: runtime error: signed integer overflow: 1073741823 * 10000 cannot be represented in type 'int'

I'll fix it.