Fix index out of range exception when invoking method.

Trying to invoke GetMethods(...) on a type when the binding flags were
passed would fail with an index out of range exception. The check that
looked for params parameters was trying to use the last parameter for
a method when the method had no parameters.
Support bitwise argument expressions.

Allows a bitwise expression to be passed as an argument to a
method.

  $type.GetMethods([System.Reflection.BindingFlags]::Instance -bor `
      [System.Reflection.BindingFlags]::Public) | % { $_.Name }