Replace hot-callsite based heuristic to use its own threshold parameter...

Replace hot-callsite based heuristic to use its own threshold parameter instead of share inline-hint parameter

Summary: Hot callsites should have higher threshold than inline hints. This patch uses separate threshold parameter for hot callsites.

Reviewers: davidxl, eraman

Subscribers: Prazek, llvm-commits

Differential Revision: https://reviews.llvm.org/D22368

llvm-svn: 277860