Remove boolean argument from isSuitableFromBSS.

The argument was used as an additional negative condition and can be
expressed in the if conditional without needing to pass it down.
Update bss commentary around main use.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@333357 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed