compiler: implement method-set based AssignableTo and Implements (#5304)

* reflect: implement method-set based AssignableTo and Implements

Based on the design from #4376 by aykevl.
Fixes #4277, fixes #3580.

Co-authored-by: Ayke van Laethem <aykevanlaethem@gmail.com>

* builder: update expected binary sizes for reflect changes

* Make interface checks similar to invoke, allowing typeImplementsMethodSet and method info to be dropped when reflect is not present

* Add more tests that BigGo reflect tests

* Even more pruning

* Add go/token and net/url to passing tests

* Prune even further, I am less happy with this, though

* Update size test now that we are smaller

* Skip some tests

* elide method lists

* format, oops

* fix tests

* Add a panic, pull out constant to keep in sync

* Add debug info

* Remove code that was leftover from a previous refactor

---------

Co-authored-by: Ayke van Laethem <aykevanlaethem@gmail.com>

testdata/reflect.txt

@@ -439,6 +439,70 @@ offset for int64 matches: true
 offset for complex128 matches: true
 type assertion succeeded for unreferenced type
 
+interface implements
+concrete implements:
+myReader → Reader: true
+*myReader → Reader: true
+myWriter → Writer: false
+*myWriter → Writer: true
+myReadWriter → Reader: true
+myReadWriter → Writer: false
+myReadWriter → ReadWriter: false
+*myReadWriter → Reader: true
+*myReadWriter → Writer: true
+*myReadWriter → ReadWriter: true
+myReader → Closer: false
+*myReadWriter → Closer: false
+errorValue → error: true
+errorValue → Stringer: false
+myErrorStringer → error: true
+myErrorStringer → Stringer: true
+myReader → interface{}: true
+int → interface{}: true
+interface implements interface:
+ReadWriter → Reader: true
+ReadWriter → Writer: true
+Reader → ReadWriter: false
+Writer → ReadWriter: false
+ReadCloser → Reader: true
+ReadCloser → Closer: true
+ReadCloser → Writer: false
+Reader → ReadCloser: false
+Reader → Reader: true
+ReadWriter → ReadWriter: true
+error → Stringer: false
+Stringer → error: false
+Reader → interface{}: true
+ReadWriter → interface{}: true
+assignable to:
+int → int: true
+string → string: true
+int → string: false
+int → int64: false
+myReader → Reader: true
+*myWriter → Writer: true
+myWriter → Writer: false
+*myReadWriter → ReadWriter: true
+ReadWriter → Reader: true
+Reader → ReadWriter: false
+int → interface{}: true
+Reader → interface{}: true
+unexported method interface:
+*notAnExpr → exprLike: true
+notAnExpr → exprLike: true
+*notAnExpr → exprLike (AssignableTo): true
+channel direction:
+chan int → <-chan int: true
+<-chan int → chan int: false
+named types:
+*int → IntPtr: true
+IntPtr → *int: true
+IntPtr → IntPtr1: false
+Ch → <-chan interface{}: true
+value set interface:
+Set[0] to BarNode: 10
+Set[1] still FooNode: 2
+
 alignment / offset:
 struct{[0]func(); byte}: true