Add --hot-func-list to llvm-profdata show for sample profiles

Summary: Add the --hot-func-list feature to llvm-profdata show for sample profiles. This feature prints a list of hot functions whose max sample count are above the 99% threshold, with their numbers of total samples, total samples percentage, max samples, entry samples, and their function names.

Reviewers: wmi, hoyFB, wenlei

Reviewed By: wmi

Subscribers: hoyFB, wenlei, llvm-commits, weihe

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D81800