Do not generate calls to fentry with __attribute__((no_instrument_function))

Do not generate calls to fentry with __attribute__((no_instrument_function))

Summary:
Currently only calls to mcount were suppressed with
no_instrument_function attribute.
Linux kernel requires that calls to fentry should also not be
generated.
This is an extended fix for PR PR33515.

Reviewers: hfinkel, rengolin, srhines, rnk, rsmith, rjmccall, hans

Reviewed By: rjmccall

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D43995

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@326639 91177308-0d34-0410-b5e6-96231b3b80d8