[GCOVProfiling] don't profile Fn's w/ noprofile attribute
Similar to D104475, the Linux kernel would like to avoid compiler
generated code in certain functions. The no_profile function
attribute can be used in C to generate the the noprofile fn attr in IR.
Respect that from GCOVProfiling.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D104257