Default Interface Method Prototype (#10505)

Default Interface Method Prototype (#10505)

* allow non-zero RVA on abstract interface method in ilasm

* Revert "allow non-zero RVA on abstract interface method in ilasm"

This reverts commit eecb8024e58f14a20e5e49359f38019f5768ac41.

* add a test case and allow virtual non-abstract method in ilasm

* allow non-abstract methods in the loader

* fixup dispatch map

* support for simple default interface method scenario

* fix a bug with incorrect usage of MethodIterator skpping the first method. add a test case for overriding but it may not be what we want

* add another simple test case for base class

* allow private/internal methods in ilasm and add a explict impl test

* update reference to mscorlib in il test

* add shared generics and variance case

* allow interface dispatch to return instantiating stubs with the right PARAM_TYPE calling conv

* simple factoring and add a valuetype test case

* add a test case for generic virtual methods

* a bit more refactoring by moving the CALLCONV_PARAMTYPE logic inside getMethodSigInternal

* support explicit methodimpl and remove implicit methodimpl test case

* update test cases to give more clear output

* Fix a bug where GetMethodDescForSlot chokes on interface MethodDesc without precode. This is accdentally discovered by methodimpl test case when iterating methods on a default interface method that has already been JITted

* cleanup code after review and add a bit more comments

* update comments

* only use custom ILAsm for default interface methods tests - some tests are choking on CoreCLR ilasm for security related stuff

* address comments and allow instance methods, and add a constraint value type call test scenario

* disable the failing protected method scenario