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>

GNUmakefile

@@ -348,6 +348,7 @@ TEST_PACKAGES_FAST = \
 	go/ast \
 	go/format \
 	go/scanner \
+	go/token \
 	go/version \
 	hash \
 	hash/adler32 \
@@ -360,6 +361,7 @@ TEST_PACKAGES_FAST = \
 	math/cmplx \
 	net/http/internal/ascii \
 	net/mail \
+	net/url \
 	os \
 	path \
 	reflect \
@@ -485,7 +487,7 @@ TEST_PACKAGES_HOST := $(TEST_PACKAGES_FAST) $(TEST_PACKAGES_WINDOWS)
 TEST_IOFS := false
 endif
 
-TEST_SKIP_FLAG := -skip='TestExtraMethods|TestParseAndBytesRoundTrip/P256/Generic'
+TEST_SKIP_FLAG := -skip='TestExtraMethods|TestParseAndBytesRoundTrip/P256/Generic|TestParseQueryLimits|TestParseStrictIpv6'
 TEST_ADDITIONAL_FLAGS ?=
 
 # Test known-working standard library packages.