llvm-cov: Added -u option for unconditional branch info.

Outputs branch information for unconditional branches in addition to
conditional branches. -b option must be enabled.

Also updated tests.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@197432 91177308-0d34-0410-b5e6-96231b3b80d8