[OpenMP] Fix broken build due to new OMPT tests

New OMPT tests with teams construct should be disabled for GCC as it
emits code with a GOMP entry not supported in the LLVM runtime.

Differential Revision: https://reviews.llvm.org/D65757


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@367939 91177308-0d34-0410-b5e6-96231b3b80d8