[ThreadSafetyAnalysis] Fix isCapabilityExpr

There are many more expr types that can be a capability expr, like
CXXThisExpr, CallExpr, MemberExpr. Instead of enumerating all of them,
just check typeHasCapability for any type given.

Also add & and * operators to allowed unary operators.

Differential Revision: https://reviews.llvm.org/D41224

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@320753 91177308-0d34-0410-b5e6-96231b3b80d8