Some debuggers like DBX on AIX assume the address in debug line entries is always incremental. But clang generates two entries (entry for file scope line and entry for prologue end) with same address if prologue is empty
And if the prologue is empty, seems the first debug line entry for the function is unnecessary(i.e. removing the first entry won't impact the behavior in GDB on Linux), so I implement this for all debuggers.
Perhaps this'd be written as: