`copilot-language`: Deprecate `forall` in favor of `forAll`. Refs #470.

[ivanperez-keera]

Introduce a new function Copilot.Language.Spec.forAll that implements the behavior currently implemented by Copilot.Language.Spec.forall, replacing all uses of the old function name and deprecating the old variant, as prescribed in the solution proposed for #470.

[ivanperez-keera]

Change Manager: Verified that:

• Solution is implemented:

  • [X] The code proposed compiles and passes all tests. Details: Build log: https://app.travis-ci.com/github/Copilot-Language/copilot/builds/268053781

  • [X] The solution proposed produces the expected result. Details: The following Dockerfile checks that the function forall has been deprecated and that the new function is offered, in which case prints the message Success. We cannot yet use a test that will produce a failure (expected) if forall is defined (i.e., with -Werror=forall-keyword) because we have to deprecate the function before we remove it.

    
    FROM ubuntu:focal

  RUN apt-get update

  RUN apt-get install --yes libz-dev RUN apt-get install --yes git

  RUN apt-get install --yes wget RUN mkdir -p $HOME/.ghcup/bin RUN wget https://downloads.haskell.org/~ghcup/0.1.19.2/x86_64-linux-ghcup-0.1.19.2 -O $HOME/.ghcup/bin/ghcup

  RUN chmod a+x $HOME/.ghcup/bin/ghcup ENV PATH=$PATH:/root/.ghcup/bin/ ENV PATH=$PATH:/root/.cabal/bin/ RUN apt-get install --yes curl RUN apt-get install --yes gcc g++ make libgmp3-dev

  SHELL ["/bin/bash", "-c"]

  RUN ghcup install ghc 9.4 RUN ghcup install cabal 3.2 RUN ghcup set ghc 9.4.8 RUN cabal update

  SHELL ["/bin/bash", "-c"] CMD git clone $REPO && cd $NAME && git checkout $COMMIT && cd .. \ && cabal v1-sandbox init \ && cabal v1-install alex happy \ && cabal v1-install copilot/**/ \ && ! cabal v1-exec -- runhaskell -Werror=deprecations <<< 'import Copilot.Language (true, forall, theorem); spec = theorem "true" (forall true); main :: IO (); main = pure ();' \ && cabal v1-exec -- runhaskell -Werror=forall-identifier -Werror=deprecations <<< 'import Copilot.Language (true, forAll, theorem); spec = theorem "true" (forAll true); main :: IO (); main = pure ();' \ && echo "Success"

  Command (adjust repo as necessary):

  $ docker run -e "REPO=https://github.com/ivanperez-keera/copilot" -e "NAME=copilot" -e "COMMIT=a7aa7678d98de2be69dd4011cb2ddac373654798" -it copilot-verify-470

• [X] Implementation is documented. Details: The new function copies the documentation from the prior one.
• [X] Change history is clear.
• [X] Commit messages are clear.
• [X] Changelogs are updated.
• [X] Examples are updated. Details: Multiple examples in the copilot and copilot-theorem repos use forall, and they are updated to use forAll.
• [X] Required version bumps are evaluated. Details: Bump needed. This alters the public API.