Make all tools that use llvmdo have a -topdir option that allows the top

Make all tools that use llvmdo have a -topdir option that allows the top
source dir for LLVM to be specified explicitly. This removes the dependency
on the llvm-config script. If the option is not given, then the scripts use
llvm-config which should be both built and in the PATH. This arrangement
provides a useful default for most developers but also allows the nightly
tester to execute countloc.sh before llvm-config is built and without
altering the PATH.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29663 91177308-0d34-0410-b5e6-96231b3b80d8