[release-branch.go1.15] runtime/pprof: skip tests for AIX
    
    Most of the time, the pprof tests are passing, except
    for the builder. The reason is still unknown but I'd rather release
    the builder to avoid missing other more important bugs.
    
    Updates #45170
    
    Change-Id: I667543ee1ae309b7319c5b3676a0901b4d0ecf2e
    Reviewed-on: https://go-review.googlesource.com/c/go/+/306489
    Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
    TryBot-Result: Go Bot <gobot@golang.org>
    Reviewed-by: Cherry Zhang <cherryyz@google.com>
    Trust: Lynn Boger <laboger@linux.vnet.ibm.com>
    (cherry picked from commit 7bfd681c2f11918c6245ad2906b2efc12eda2914)
    Reviewed-on: https://go-review.googlesource.com/c/go/+/317369
    Reviewed-by: Heschi Kreinick <heschi@google.com>
    Trust: Dmitri Shuralyov <dmitshur@golang.org>
    Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>