Rotate two of the functions used to count bonuses for the inline cost

Rotate two of the functions used to count bonuses for the inline cost
analysis to be methods on the cost analysis's function info object
instead of the code metrics object. These really are just users of the
code metrics, they're building the information for the function's
analysis.

This is the first step of growing the amount of information we collect
about a function in order to cope with pair-wise simplifications due to
allocas.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152283 91177308-0d34-0410-b5e6-96231b3b80d8