The F-117 was purpose built to do one thing VERY well.
1) Take two precision guided munitions.
2) Carry them to a high value target which would be usually very well defended
3) Use stealth technology to defeat these threats
4) Hit these targets using mostly passive targeting systems, which also serve to defeat threats
5) Safely return to base to do it all over again
Changing this aircraft into a "fighter" instead of a precision attack/interdication aircraft would not make sense.
If the -117 carried Aim-9's, it could not carry any bombs. It only has two internal hardpoints.
"A jack of all trades is usually a specialist at none"