Noted slowness in profile loading with binutils 2.37

[Nick Clifton]

Hi Alexander,

> So it looks like you were spot-on

Yay!

The sad news is that the patch is needed for correct functionality.

>                  PR 27484
>                  * dwarf2.c (scan_unit_for_symbols): Scan twice, once to accumulate
>                  function and variable tags and a second time to resolve their
>                  attributes.

It is a "feature" of the DWARF spec that the debug info can refer
to functions and variables before their definitions are provided,
so a two pass scan is needed.

If you are feeling brave, please feel free to investigate the code
in dwarf2.c and see if there is a faster way to solve the problem.
Maybe by implementing a lazy evaluation of attributes where a function
tag is only searched for when it is referenced ?  Just an idea...

Cheers
   Nick