[LLDB][MIPS] A small fix in GetBreakableLoadAddress() for MIPS

    
    SUMMARY:
    Get the load address for the address given by symbol and function.
    Earlier, this was done for function only, this patch does it for symbol too.
    This patch also adds TestAvoidBreakpointInDelaySlot.py to test this change.
    
    Reviewers: clayborg
    Subscribers: labath, zturner, mohit.bhakkad, sagar, jaydeep, lldb-commits
    Differential Revision: http://reviews.llvm.org/D16049

llvm-svn: 258919