cmd/internal/link: disable selected DWARF tests on Solaris

cmd/internal/link: disable selected DWARF tests on Solaris

Disable the three linker DWARF tests that invoke the compiler in
non-debug mode on Solaris, since this seems to trigger a split stack
overflow. These can be turned back on once the issue in question is
resolved.

Updates #23168.

Change-Id: I5be1b098e33e8bad3bc234a0964eab1dee7e7954
Reviewed-on: https://go-review.googlesource.com/84655
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Than McIntosh <thanm@google.com>