Give plugins a better interface (#17957)

Plugins were directly fetched from HscEnv (hsc_static_plugins and
hsc_plugins). The tight coupling of plugins and of HscEnv is undesirable
and it's better to store them in a new Plugins datatype and to use it in
the plugins' API (e.g. withPlugins, mapPlugins...).

In the process, the interactive context (used by GHCi) got proper
support for different static plugins than those used for loaded modules.

Bump haddock submodule

1 files changed, 0 insertions, 0 deletions

diff --git a/utils/haddock b/utils/haddock
-Subproject bbe3c508cc5688683f9febbed814e5230dce0c4
+Subproject 00e7d92f372c706dfd749d824c8c97d38383c25