internal/testtext: override behavior of AllocsPerRun for gccgo

At least until escape analysis is improved for gccgo.

Fixes golang/go#16135

Change-Id: I6c98d6650ca4be6d8d5eb704764df297b3f4dace
Reviewed-on: https://go-review.googlesource.com/24495
Reviewed-by: Nigel Tao <nigeltao@golang.org>
Run-TryBot: Marcel van Lohuizen <mpvl@golang.org>
8 files changed