[ASTMatcher] Extend hasAnyArgument to ObjCMessageExpr

Currently hasArgument works with both ObjC messages and function calls,
but not hasAnyArgument.
This patch fixes that discrepancy, as it's often more convenient to use
hasAnyArgument.

On a more general note, it would be great to have a common superclass
for objc-call and function call, and a matcher matching that, but that's
probably a job for another commit.

Differential Revision: https://reviews.llvm.org/D44169

llvm-svn: 326865