Type inference for inline consts

[nbdd0121]

Fixes #78132
Fixes #78174
Fixes #81857
Fixes #89964

Perform type checking/inference of inline consts in the same context as the outer def, similar to what is currently done to closure.

Doing so would require closure_base_def_id of the inline const to return the outer def, and since closure_base_def_id can be called on non-local crate (and thus have no HIR available), a new DefKind is created for inline consts.

The type of the generated anon const can capture lifetime of outer def, so we couldn't just use the typeck result as the type of the inline const's def. Closure has a similar issue, and it uses extra type params CK, CS, U to capture closure kind, input/output signature and upvars. I use a similar approach for inline consts, letting it have an extra type param R, and then typeof(InlineConst<[paremt generics], R>) would just be R. In borrowck region requirements are also propagated to the outer MIR body just like it's currently done for closure.

With this PR, inline consts in expression position are quitely usable now; however the usage in pattern position is still incomplete -- since those does not remain in the MIR borrowck couldn't verify the lifetime there. I have left an ignored test as a FIXME.

Some disucssions can be found on this Zulip thread.
cc @spastorino @lcnr
r? @nikomatsakis

@rustbot label A-inference F-inline_const T-compiler