Place the "cold" code piece into the same section as the original function

Summary:
This cropped up in the Linux kernel where cold code was placed in an
incompatible section.

Reviewers: compnerd, vsk, tejohnson

Reviewed By: vsk

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70925