If we use is also, we need to check the class we're trying to extend already exists.

Merge branch 'master' of git@github.com:rakudo/rakudo

If optional parameter not supplied, don't do type checks. Resolves RT#61528 and RT#63048.

Add parsing of $/ as a param_var (RT #63152).

Improve handling of <-> so any traits explicitly set in the signature are not overridden with rw.

Implement <-> (lambda that makes things rw), which gets S04-statements/for.t passing again.

Add 'make' function (partial RT #63152, chrisdolan++)

++ and -- in both their prefix and postfix forms now use infix:<=>, which means they do read-only checking properly. This corrects RT#60380, but does cause some failures in for.t since <-> is not implemented, but accidentally worked before; will fix that in my next commit.

Add S05-grammar/parse_and_parsefile.t to spectests.

Avoid an infinite exception handler loop by popping a handler before calling Rakudo's 'die'. Resolves RT#62700.

Implement .parsefile method on Grammar.

A few more panics on malformed code from STD.pm. Resolves RT#59828.

Add panic on malformed declaration, as seen in STD.pm (with note on our little difference against STD.pm). Also we accidentally parsed/passed a private method test; add something to mitigate that to keep the spectests clean.

We need to call .clone() rather than just using Parrot's clone vtable method fairly generally, I expect. This does that in a couple of places, which in turn resolves RT#63002 and gets an integration test passing.

Fix .clone to deref ObjectRefs properly by calling !DEREF, which follows chains. Resolves RT#62828.

Fixes to make sure dispatches on proto-objects work correctly; resolves RT#62894.

[config] Configure needs to translate forward slashes in makefile to backwards ones for Win32, as Parrot's Configure did. Otherwise the build silently misses a bunch of important bits!