"asm printering" happens through MCStreamer. This also
Streamerizes PIC16 debug info, which escaped my attention.
This removes a leak from LLVMTargetMachine of the 'legacy'
output stream.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100327 91177308-0d34-0410-b5e6-96231b3b80d8