Find the original method for the Java5 bridge Method. If the supplied method
is not a bridge method then the supplied method is returned.
If the supplied method is a bridge method, the algorithm tries to find a more
specific method with parameters and return types that can be assigned to the
the supplied method parameters and return type.
Informally, method A is more specific than method B if
any invocation handled by method A can also be handled by method B.
bridgeMethod - the bridge method (Java 5 specific)
targetClass - the class the method belongs to
the original method or a more specific method if available