[llgo] Disable known failing packages in check-libgo

Summary:
There are two packages in libgo which have
known failures when running the "make check" rule.
This change disables those packages in the tests so
that we can run libgo tests without them until the
root causes are identified and resolved.

Test Plan: ran check-libgo rule

Reviewers: pcc

Reviewed By: pcc

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D8003

llvm-svn: 231448