Fix AST matcher documentation for overloaded matchers.

Before this patch we would only use the fist occurance of a matcher
function in the documentation, for example leaving out
hasType(Matcher<QualType>).

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@202019 91177308-0d34-0410-b5e6-96231b3b80d8