xas99 metrics on assembly process

[MirrorPusher]

Would be cool to have some performance metrics on the assembly process.

For example:

• Total amount of CPU instructions processed
• Total amount of data definition instructions processed
• Number of CPU instructions per second
• Walltime used for assembly process

Also interesting:

• Metrics on instructions per instruction set type (# of mov statement)
• Instructions per instruction size
• ....