[Xamarin.Android.Tools.Bytecode] Support @JvmOverloads

[jonpryor]

@moljac ran into an interesting warning from class-parse when
binding OfficeUIFrabric:

warning : class-parse: warning: method com/microsoft/officeuifabric/widget/BottomNavigationView.<init>(Landroid/content/Context;)V: Local variables array has 0 entries ('LocalVariableTableAttribute(LocalVariableTableEntry(Name='context', Descriptor='Landroid/content/Context;'))'); descriptor has 1 entries!

For starters, this shouldn't be a warning; it's not actionable.
There is nothing a user can do to fix this warning; it's only
meaningful to the Java.Interop team.

Update Xamarin.Android.Tools.Bytecode.MethodInfo.GetParameters() so
that these messages are debug messages, not warnings.

class-parse knows how many parameters are present based on the JNI
method descriptor, in this case (Landroid/content/Context;)V, which
specifies one parameter type. The JNI descriptor doesn't contain
parameter name information; where do parameter names come from?

If the .class file was built via javac -parameters, then the
MethodParametersAttribute blob can be used; see 4273e5c.

However, before checking for MethodParametersAttribute,
class-parse will attempt to use the LocalVariableTableAttribute
and LocalVariableTableEntry values to infer parameter names.
As part of this inference, method parameters are assumed to be
variables with LocalVariableTableEntry.StartPC is 0; from
class-parse --dump BottomNavigationView.class:

LocalVariableTableAttribute(
  LocalVariableTableEntry(Name='context', Descriptor='Landroid/content/Context;', StartPC=0, Index=1))

Next, class-parse will "skip" the first variable for instance
methods. This results in "skipping" the context variable, resulting
in the message:

Local variables array has 0 entries …; descriptor has 1 entries!

To fix this, class-parse needs a stricter "skip the this
parameter" check: the first parameter should only be skipped when:

1. The method is an instance method, not a static method, and
2. The JNI descriptor of the first parameter is the same as the
   descriptor of the declaring type.

Additionally, update the code style to use enumValue.HasFlag(V)
instead of (enumValue & V) == V for readability.

Finally, why was this failing in the first place? In some
circumstances, when the Kotlin [@JvmOverloads][2] annotation is used
on a constructor, Kotlin will emit all possible overloads for the
constructor, and in many of those overloads the this parameter
won't be present in the LocalVariableTableAttribute data, as seen
above with BottomNavigationView.