Propagate all closure requirements to the caller

[matthewjasper]

Closes #56477

This should be backported to 1.32 if it doesn't make the cut.

r? @pnkfelix
cc @nikomatsakis

[rust-highfive]

The job x86_64-gnu-llvm-5.0 of your PR failed on Travis (raw log). Through arcane magic we have determined that the following fragments from the build log may contain information about the problem.

Click to expand the log.

travis_time:end:0932e2f0:start=1543879274842536031,finish=1543879276088840360,duration=1246304329
$ git checkout -qf FETCH_HEAD
travis_fold:end:git.checkout

Encrypted environment variables have been removed for security reasons.
See https://docs.travis-ci.com/user/pull-requests/#Pull-Requests-and-Security-Restrictions
$ export SCCACHE_BUCKET=rust-lang-ci-sccache2
$ export SCCACHE_REGION=us-west-1
Setting environment variables from .travis.yml
$ export IMAGE=x86_64-gnu-llvm-5.0
---
[00:29:15] error: unsatisfied lifetime constraints
[00:29:15]    --> src/librustc_typeck/check/wfcheck.rs:358:5
[00:29:15]     |
[00:29:15] 350 | fn check_item_type<'a, 'tcx>(
[00:29:15]     |                    --  ---- lifetime `'tcx` defined here
[00:29:15]     |                    lifetime `'a` defined here
[00:29:15] ...
[00:29:15] ...
[00:29:15] 358 |     for_id(tcx, item_id, ty_span).with_fcx(|fcx, _this| {
[00:29:15]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ argument requires that `'a` must outlive `'tcx`
[00:29:15] 
[00:29:15] error[E0716]: temporary value dropped while borrowed
[00:29:15]    --> src/librustc_typeck/check/wfcheck.rs:358:5
[00:29:15] 350 |   fn check_item_type<'a, 'tcx>(
[00:29:15] 350 |   fn check_item_type<'a, 'tcx>(
[00:29:15]     |                          ---- lifetime `'tcx` defined here
[00:29:15] ...
[00:29:15] 358 |       for_id(tcx, item_id, ty_span).with_fcx(|fcx, _this| {
[00:29:15]     |       -^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[00:29:15]     |       |
[00:29:15]     |  _____creates a temporary which is freed while still in use
[00:29:15]     | |
[00:29:15] 359 | |         let ty = fcx.tcx.type_of(fcx.tcx.hir.local_def_id(item_id));
[00:29:15] 360 | |         let item_ty = fcx.normalize_associated_types_in(ty_span, &ty);
[00:29:15] ...   |
[00:29:15] ...   |
[00:29:15] 378 | |         vec![] // no implied bounds in a const etc
[00:29:15] 379 | |     });
[00:29:15]     | |      -- temporary value is freed at the end of this statement
[00:29:15]     | |______|
[00:29:15]     |        argument requires that borrow lasts for `'tcx`
[00:29:17] error: aborting due to 2 previous errors
[00:29:17] 
[00:29:17] For more information about this error, try `rustc --explain E0716`.
[00:29:17] error: Could not compile `rustc_typeck`.

I'm a bot! I can only do what humans tell me to, so if this was not helpful or you have suggestions for improvements, please ping or otherwise contact @TimNN. (Feature Requests)

[pnkfelix]

oh wow what a bug!

[pnkfelix]

@bors r+ p=1

[bors]

📌 Commit d748712 has been approved by pnkfelix

[matthewjasper]

@bors r- investigating build failure.

[matthewjasper]

@bors r=pnkfelix

[bors]

📌 Commit b2e6da7 has been approved by pnkfelix

[bors]

⌛ Testing commit b2e6da7 with merge b3af092...

[Mark-Simulacrum]

@bors p=10

[pietroalbini]

This is going to be included in the 1.31.0 release: #56518

[bors]

☀️ Test successful - status-appveyor, status-travis
Approved by: pnkfelix
Pushing b3af092 to master...