[analyzer] Fix ExprEngine::VisitMemberExpr

AST may contain intermediate ParenExpr nodes
between MemberExpr and ArrayToPointerDecay.
This diff adjusts the check in ExprEngine::VisitMemberExpr accordingly.
Test plan: make -j8 check-clang-analysis

Differential revision: https://reviews.llvm.org/D24484


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@281373 91177308-0d34-0410-b5e6-96231b3b80d8