For blocks that are not loop headers, just print their loop depth and header BB.

For loop headers, print Inner loop along with the other stuff so it doesn't take
an extra line.  We now get stuff like this:

LBB1_4:                                                     ## %land.end
                                                            ##   in Loop: Header=BB1_1 Depth=1
        notb    %al
        testb   $1, %al
        jne     LBB1_8

and:

LBB1_6:                                                     ## %while.cond7
                                                            ## Inner Loop Header: Depth=3
                                                            ##     Inside Loop BB1_5 Depth 2
                                                            ##   Inside Loop BB1_1 Depth 1

which still isn't great for loop headers, but is much less verbose.

llvm-svn: 94221