Printing the live ranges of virtual registers.

Today I coded a little pass to print all the live range information.
LLVM stores this information in the LiveVariables class.
Basically, for each variable it holds:

• Unique definition point;
  
  
• Blocks that are crossed by the live range of the variable;
  
  
• Blocks where the live range is killed, that is, where it is used for the last time.
  
  

The code to print such information is very simple.