[sanitizer-coverage] Return the array from CreatePCArray. NFC

Be more consistent with CreateFunctionLocalArrayInSection in the API
of CreatePCArray, and assign the member variable in the caller like we
do for the guard and 8-bit counter arrays.

This also tweaks the order of method declarations to match the order
of definitions in the file.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@311955 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed