Remove unzip() SizeHint hack
This was using an invalid iterator so is likely to end with buggy
behaviour.
It also doesn't even benefit many type in std including Vec so removing it
shouldn't cause any problems.
Fixes: #33468
trans: generalize immediate temporaries to all MIR locals.
Added `Mir::local_index` which gives you an unified index for `Arg`, `Var`, `Temp` and `ReturnPointer`.
Also available is `Mir::count_locals` which returns the total number of the above locals.
This simplifies a lot of the code which can treat all of the local lvalues in the same manner.
If we had `-> impl Iterator`, I could have added a bunch of useful `Ty` or `Lvalue` iterators for all locals.
We could of course manually write such iterators as they are needed.
The only place which currently takes advantage of unified locals is trans' alloca elision.
Currently it's not as good as it could be, due to our usage of `llvm.dbg.declare` in debug mode.
But passing some arguments and variables as immediates has some effect on release-mode `libsyntax`:
Old trans:
```
time: 11.500; rss: 710MB translation
time: 0.002; rss: 710MB assert dep graph
time: 0.000; rss: 710MB serialize dep graph
time: 4.410; rss: 628MB llvm function passes [0]
time: 84.485; rss: 633MB llvm module passes [0]
time: 23.898; rss: 634MB codegen passes [0]
time: 0.002; rss: 634MB codegen passes [0]
time: 113.408; rss: 634MB LLVM passes
```
`-Z orbit`, previously:
```
time: 12.588; rss: 723MB translation
time: 0.002; rss: 723MB assert dep graph
time: 0.000; rss: 723MB serialize dep graph
time: 4.597; rss: 642MB llvm function passes [0]
time: 77.347; rss: 646MB llvm module passes [0]
time: 24.703; rss: 648MB codegen passes [0]
time: 0.002; rss: 615MB codegen passes [0]
time: 107.233; rss: 615MB LLVM passes
```
`-Z orbit`, after this PR:
```
time: 13.820; rss: 672MB translation
time: 0.002; rss: 672MB assert dep graph
time: 0.000; rss: 672MB serialize dep graph
time: 3.969; rss: 591MB llvm function passes [0]
time: 72.294; rss: 595MB llvm module passes [0]
time: 24.610; rss: 597MB codegen passes [0]
time: 0.002; rss: 597MB codegen passes [0]
time: 101.439; rss: 597MB LLVM passes
```
Implementation of #34168
r? @brson
cc @alexcrichton
cc @steveklabnik
cc @jonathandturner
I only updated `librustc_privacy/diagnostics.rs`, and I already found a case where the code doesn't throw the expected error code (E0448).
Fixes#34168.
- src links/redirects to extern fn from another crate had an extra '/'.
- src links to `pub use` of a crate module had an extra '/'.
- src links to renamed reexports from another crate used the new name
for the link but should use the original name.
We no C++ and an incredibly small amount of C code as part of the build, so
there's not really much need for us to strictly check the version of compilers
as we're not really stressing anything. LLVM is a pretty huge chunk of C++ but
it should be the responsibility of LLVM to ensure that it can build with a
particular clang/gcc version, not ours (as this logic changes over time).
These version checks seem to basically just by us a regular stream of PRs every
six weeks or so when a new version is releases, so they're not really buying us
much. As a result, remove them and we can add then back piecemeal perhaps as a
blacklist if we really need to.
Pretty-print attributes on tuple structs and add tests
This adds support to the pretty printer to print attributes added to tuple struct elements. Furthermore, it adds a test that makes sure we will print attributes on all variant data types.
Fix ICE in memory categorization of tuple patterns
Fixes https://github.com/rust-lang/rust/issues/34334
It seems to be ok for `pat_ty` to return `Err` even if type checking is done, because it uses `infcx.node_ty` which is supposed to return `Err` for all kinds of erroneous types so its callers could quickly bail out with `?`.
r? @arielb1
