[ICP] Remove incompatible attributes at indirect-call promoted callsites.

Summary:
Removing ncompatible attributes at indirect-call promoted callsites, not removing it results in
at least a IR verification error.

Reviewers: davidxl, xur, mssimpso

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D54913

llvm-svn: 347605