go/internal/gccgoimporter: test fix for older gccgo versions
Avoid running the test for issue 29198 if the available copy of gccgo
is too old (needs to support context package). Fixes a failure on the
solaris builder.
Updates #29198.
Change-Id: I2b1b3438f4ac105432f30078fbef78e24f2077cd
Reviewed-on: https://go-review.googlesource.com/c/153831
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>