Change debug-info-for-profiling from a TargetOption to a function attribute.

Summary: cfe change for https://reviews.llvm.org/D29203

Reviewers: echristo, dblaikie

Reviewed By: dblaikie

Subscribers: mehdi_amini, cfe-commits

Differential Revision: https://reviews.llvm.org/D29205

llvm-svn: 293834