Expand `managedOverride` for `none`

[jpobst]

In #701, we created the managedOverride metadata which allows a user to override which of virtual/override keywords are placed on a method:

<attr path="//method[@name='example']" name="managedOverride">override</attr>
<attr path="//method[@name='example']" name="managedOverride">virtual</attr>

However, sometimes the desired fix is "none of the above". For example, there may not be a method to override, however the class is sealed so virtual is not a valid option either. Both keywords must be omitted.

We should add support for a third none option:

<attr path="//method[@name='example']" name="managedOverride">none</attr>

[jonpryor]

Tangentially related is this TODO from a65d6fb:

The problem here is that we have:

public partial interface IAnnotatedType {
    // Contains default interface method
    virtual unsafe IAnnotatedType? AnnotatedOwnerType => …;
}
public partial interface IAnnotatedArrayType : IAnnotatedType {
    // Contains *no* method body; re-abstracted
    IAnnotatedType? AnnotatedOwnerType {get;}
}

TODO: figure out how to properly fix this. managedOverride
metadata (5a0e37e) doesn't seem useful to "re-abstract" a default
interface member.

The solution is to "reabstract" the member:

public partial interface IAnnotatedType {
    // Contains default interface method
    virtual IAnnotatedType? AnnotatedOwnerType => null;
}
public partial interface IAnnotatedArrayType : IAnnotatedType {
    // Contains *no* method body; re-abstracted
    abstract IAnnotatedType? IAnnotatedType.AnnotatedOwnerType {get;}
}

The question is how to "reabstract" IAnnotatedType.AnnotatedOwnerType within generator & Metadata? A plausible answer may be to use propertyName to change AnnotatedArrayType.getAnnotatedOwnerType() to IAnnotatedType.AnnotatedOwnerType:

  <attr path="/api/package[@name='java.lang.reflect']/interface[@name='AnnotatedArrayType']/method[@name='getAnnotatedOwnerType' and count(parameter)=0]"
      name="propertyName">IAnnotatedType.AnnotatedOwnerType</attr>

This partially works:

public partial interface IAnnotatedArrayType : global::Java.Lang.Reflect.IAnnotatedType {
	global::Java.Lang.Reflect.IAnnotatedType? IAnnotatedType.AnnotatedOwnerType {
		// Metadata.xml XPath method reference: path="/api/package[@name='java.lang.reflect']/interface[@name='AnnotatedArrayType']/method[@name='getAnnotatedOwnerType' and count(parameter)=0]"
		[global::Java.Interop.JniMethodSignature ("getAnnotatedOwnerType", "()Ljava/lang/reflect/AnnotatedType;")]
		get; 
	}
}

However, it fails to compile:

Java.Lang.Reflect.IAnnotatedArrayType.cs(19,4): error CS0501: 
'IAnnotatedArrayType.IAnnotatedType.AnnotatedOwnerType.get' must declare a body because it is not marked abstract, extern, or partial

Thus, a fourth managedOverride value of abstract could be useful:

  <attr path="/api/package[@name='java.lang.reflect']/interface[@name='AnnotatedArrayType']/method[@name='getAnnotatedOwnerType' and count(parameter)=0]"
      name="managedOverride">abstract</attr>

Which, in combination with the propertyName override, would emit:

public partial interface IAnnotatedArrayType : global::Java.Lang.Reflect.IAnnotatedType {
	abstract global::Java.Lang.Reflect.IAnnotatedType? IAnnotatedType.AnnotatedOwnerType {
		// Metadata.xml XPath method reference: path="/api/package[@name='java.lang.reflect']/interface[@name='AnnotatedArrayType']/method[@name='getAnnotatedOwnerType' and count(parameter)=0]"
		[global::Java.Interop.JniMethodSignature ("getAnnotatedOwnerType", "()Ljava/lang/reflect/AnnotatedType;")]
		get; 
	}
}

(Another question on our call earlier today was whether or not this would be "enough". These two fixes are "enough" to get the current src/Java.Base to build, which is a data point, but I don't know for certain if setting propertyName to IAnnotatedType.AnnotatedOwnerType will always work.)

[jpobst]

Thus, a fourth managedOverride value of abstract could be useful:

Is this not fixed by setting abstract to true?

<attr path="/api/package[@name='java.lang.reflect']/interface[@name='AnnotatedArrayType']/method[@name='getAnnotatedOwnerType' and count(parameter)=0]"
      name="abstract">true</attr>

[jonpryor]

@jpobst asked:

Is this not fixed by setting abstract to true?

It's already true; obj/Debug-net6.0/mcw/api.xml.adjusted.fixed contains:

    <interface abstract="true" deprecated="not deprecated" final="false" name="AnnotatedArrayType" static="false" visibility="public" jni-signature="Ljava/lang/reflect/AnnotatedArrayType;">
      <implements name="java.lang.reflect.AnnotatedType" name-generic-aware="java.lang.reflect.AnnotatedType" jni-type="Ljava/lang/reflect/AnnotatedType;" />
      <method abstract="true" deprecated="not deprecated" final="false" name="getAnnotatedGenericComponentType" jni-signature="()Ljava/lang/reflect/AnnotatedType;" bridge="false" native="false" return="java.lang.reflect.AnnotatedType" jni-return="Ljava/lang/reflect/AnnotatedType;" static="false" synchronized="false" synthetic="false" visibility="public" />
      <method abstract="true" deprecated="not deprecated" final="false" name="getAnnotatedOwnerType" jni-signature="()Ljava/lang/reflect/AnnotatedType;" bridge="false" native="false" return="java.lang.reflect.AnnotatedType" jni-return="Ljava/lang/reflect/AnnotatedType;" static="false" synchronized="false" synthetic="false" visibility="public" propertyName="IAnnotatedType.AnnotatedOwnerType" />
    </interface>

Yet abstract isn't emitted, presumably because this is on an interface, and thus members are already assumed to be implicitly abstract?

[jpobst]

I went with reabstract to denote this is only needed/supported for interface methods/properties. Normal class members should be controlled with the usual abstract='true' XML.