For example, `foo::<T>::bar::<U>`.

This doesn't enforce that the type parameters are in the right
positions, however.

They are still present as part of the borrow check.

Fixes for #8625 to prevent assigning to `&mut` in borrowed or aliasable locations. The old code was insufficient in that it failed to catch bizarre cases like `& &mut &mut`. 

r? @pnkfelix

`target_library_in_workspace` is imported but unused:
~/rust/src/librustpkg/tests.rs:21:48: 21:75 warning: unused import [-W unused-imports (default)]

`UnsafeAtomicRcBox` → `UnsafeArc` (#7674), and `AtomicRcBoxData` → `ArcData` to reflect this.

Also, the inner pointer of `UnsafeArc` is now `*mut ArcData`, which avoids some transmutes to `~`: i.e. less chance of mistakes.

As for now, rekillable is an unsafe function, instead, it should behave
just like unkillable by encapsulating unsafe code within an unsafe
block.

This patch does that and removes unsafe blocks that were encapsulating
rekillable calls throughout rust's libs.

Fixes #8232

Closes #6002 

There is consensus that the current implementation should be changed or
removed, so removing it seems like the right decision for now.

Closes #6002

There is consensus that the current implementation should be changed or
removed, so removing it seems like the right decision for now.

Fix #6887.  (or rather, a bug injected by my prior commit for fixing that bug.)

This means that fewer `transmute`s are required, so there is less
chance of a `transmute` not having the corresponding `forget`
(possibly leading to use-after-free, etc).

This callstack changed when the FFI did. I am still a little frightened by
this suppression.

cc #8253

r? anyone. Now, rustpkg --version does something useful!

Now that new LLVM has landed, the debug info works on Windows as well.   Most existing tests pass, except for the following four, which I left disabled for now:
lexical-scope-in-for-loop
lexical-scope-in-if
lexical-scope-in-match
lexical-scopes-in-block-expression

Also, fixed a small problem with the debug info test runner.

Beforehand, it was unclear whether rust was performing the "recommended set" of
optimizations provided by LLVM for code. This commit changes the way we run
passes to closely mirror that of clang, which in theory does it correctly. The
notable changes include:

* Passes are no longer explicitly added one by one. This would be difficult to
  keep up with as LLVM changes and we don't guaranteed always know the best
  order in which to run passes
* Passes are now managed by LLVM's PassManagerBuilder object. This is then used
  to populate the various pass managers run.
* We now run both a FunctionPassManager and a module-wide PassManager. This is
  what clang does, and I presume that we *may* see a speed boost from the
  module-wide passes just having to do less work. I have no measured this.
* The codegen pass manager has been extracted to its own separate pass manager
  to not get mixed up with the other passes
* All pass managers now include passes for target-specific data layout and
  analysis passes

Some new features include:

* You can now print all passes being run with `-Z print-llvm-passes`
* When specifying passes via `--passes`, the passes are now appended to the
  default list of passes instead of overwriting them.
* The output of `--passes list` is now generated by LLVM instead of maintaining
  a list of passes ourselves
* Loop vectorization is turned on by default as an optimization pass and can be
  disabled with `-Z no-vectorize-loops`


All of these "copies" of clang are based off their [source code](http://clang.llvm.org/doxygen/BackendUtil_8cpp_source.html) in case anyone is curious what my source is. I was hoping that this would fix #8665, but this does not help the performance issues found there. Hopefully i'll allow us to tweak passes or see what's going on to try to debug that problem.

Beforehand, it was unclear whether rust was performing the "recommended set" of
optimizations provided by LLVM for code. This commit changes the way we run
passes to closely mirror that of clang, which in theory does it correctly. The
notable changes include:

* Passes are no longer explicitly added one by one. This would be difficult to
  keep up with as LLVM changes and we don't guaranteed always know the best
  order in which to run passes
* Passes are now managed by LLVM's PassManagerBuilder object. This is then used
  to populate the various pass managers run.
* We now run both a FunctionPassManager and a module-wide PassManager. This is
  what clang does, and I presume that we *may* see a speed boost from the
  module-wide passes just having to do less work. I have no measured this.
* The codegen pass manager has been extracted to its own separate pass manager
  to not get mixed up with the other passes
* All pass managers now include passes for target-specific data layout and
  analysis passes

Some new features include:

* You can now print all passes being run with `-Z print-llvm-passes`
* When specifying passes via `--passes`, the passes are now appended to the
  default list of passes instead of overwriting them.
* The output of `--passes list` is now generated by LLVM instead of maintaining
  a list of passes ourselves
* Loop vectorization is turned on by default as an optimization pass and can be
  disabled with `-Z no-vectorize-loops`

Fix #6887

This is a pull request for #2275

I've created a small python script to generate test files for a list of keywords (as break do else enum extern false fn for if impl let loop match mod mut priv pub ref return self static struct super true trait type unsafe use while), but I'm not really sure where to put it. I've added the created files as well.

I did not use 

     fn main() {
        let $KW = "foo"; //~ error
        println($KW); //~ error
    } 

as template, because for return, self, ref, loop, mut and break this does not raise an error in the ```println``` line, only in the ```let``` line.

This callstack changed when the FFI did. I am still a little frightened by
this suppression.

r? @brson ...multiple workspaces

The test checks that rustpkg uses the first one, rather than complaining
about multiple matches.

Closes #7241