[OPENMP] Fix for http://llvm.org/PR24674: assertion failed and and abort trap

[OPENMP] Fix for http://llvm.org/PR24674: assertion failed and and abort trap
Fix processing of shared variables with reference types in OpenMP constructs. Previously, if the variable was not marked in one of the private clauses, the reference to this variable was emitted incorrectly and caused an assertion later.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@246846 91177308-0d34-0410-b5e6-96231b3b80d8