Fixes rust-lang#41213.

The book and the reference have both had changes lately; this integrates
them upstream.

No good reason for them to be in there.

These do some low-level munging on the LLVM data structures. Unclear
that they need to operate as a "second pass" but leave it for now.

A number of things were using `crate_hash` that really ought to be using
`crate_disambiguator` (e.g., to create the plugin symbol names). They
have been updated.

It is important to remove `LinkMeta` from `SharedCrateContext` since it
contains a hash of the entire crate, and hence it will change
whenever **anything** changes (which would then require
rebuilding **everything**).

shared mutable state is bad

Its going to be forbidden, see issue 41255.

…ikomatsakis

rustc_typeck: consolidate adjustment composition

Instead of having `write_adjustment` overwrite the previous adjustment, have `apply_adjustment` compose a new adjustment on top of the previous one. This is important because `NeverToAny` adjustments can be present on expressions during coercion.

Fixes rust-lang#41213.

r? @nikomatsakis

…guillaumegomez

bump book repos

Not ready to merge yet; I'd like to see what tidy says.

…ns, r=eddyb

Miscellneous refactorings of trans

This doesn't achieve any particular goal yet, but it's a collection of refactorings with the common goal of turning `SharedCrateContext` etc into stuff that we can use with on-demand and actually expect to hash in a stable fashion for incremental. Not there yet, clearly.

r? @eddyb
cc @michaelwoerister

Avoid to use floating point match

Its going to be forbidden, see issue rust-lang#41255.