Move the inline cost analysis's primary cost query to TTI instead of the
old CodeMetrics system. TTI has the specific advantage of being
extensible and customizable by targets to reflect target-specific cost
metrics.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173032 91177308-0d34-0410-b5e6-96231b3b80d8