cmd/cover: fix buglet causing differences in -m output
Use a slightly different line number pragma when emitting instrumented
code, so as to ensure that we don't get any changes in the
"-gcflags=-m" output for coverage vs non-coverage.
Fixes #56475.
Change-Id: I3079171fdf83c0434ed6ea0ce3eb2797c2280c55
Reviewed-on: https://go-review.googlesource.com/c/go/+/446259
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Than McIntosh <thanm@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com>