Change the "breakpoint fuzz" algorithm from "coalesce the line ranges for a...

Change the "breakpoint fuzz" algorithm from "coalesce the line ranges for a file & line breakpoint if they are contiguous" to 
"coalesce the line ranges for a file & line breakpoint to the first range in each block".  We were still setting a silly number
of independent breakpoints sometimes, and until we get a compiler that emits trustworthy is_stmt flags in the line table, we
need to do something to reduce the noise.

<rdar://problem/14920404>

llvm-svn: 190380