[Inliner] Add another way to compute full inline cost.

Summary:
Full inline cost is computed when -inline-cost-full is true or ORE is
non-null. This patch adds another way to compute full inline cost by
adding a field to InlineParams. This will be used by SampleProfileLoader
to check legality of inlining a callee that it wants to inline.

Reviewers: danielcdh, haicheng

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D37819

llvm-svn: 313185