This part of the revised Nios II prologue/epilogue refactoring patch 
fixes the prologue analyzer to handle the multiple stack adjustment 
instructions that GCC may now emit in some cases.  It replaces the test 
that caused analysis to terminate when a second adjustment is found with 
more specific tests that can distinguish between prologue-ish and 
epilogue-ish adjustments.

OK to commit on top of part 1?

-Sandra