[Clang] Handle interaction of -pg and no_instrument_function attribute.

Summary:
Disable generation of counting-function attribute if no_instrument_function
attribute is present in function.
Interaction between -pg and no_instrument_function is the desired behavior
and matches gcc as well.
This is required for fixing a crash in Linux kernel when function tracing
is enabled.

Fixes PR33515.

Reviewers: hfinkel, rengolin, srhines, hans

Reviewed By: hfinkel

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D34357

llvm-svn: 305728