Initial support for emitting DWARF for static vars.

Only supports crate level statics. No debug info is generated for
function level statics. Closes #9227.
Register new snapshot
dist: Tweak the OSX pkg installer

This performs a few touch-ups to the OSX installer:

* A rust logo is shown during installation
* The installation happens to /usr/local by default (instead of /)
* A new welcome screen is shown that's slightly more relevant
configure uses `command -v` instead of `which` #13147
auto merge of #13185 : alexcrichton/rust/osx-pkg, r=brson

This performs a few touch-ups to the OSX installer:

* A rust logo is shown during installation
* The installation happens to /usr/local by default (instead of /)
* A new welcome screen is shown that's slightly more relevant
auto merge of #13188 : FlaPer87/rust/master, r=alexcrichton
auto merge of #13193 : pongad/rust/fixconfig, r=thestinger

Fixes #13147

Not a shell pro myself, though after running the new config, make and make check still work ok.
auto merge of #13143 : gentlefolk/rust/issue-9227, r=michaelwoerister

Only supports crate level statics. No debug info is generated for function level statics. Closes #9227.

As discussed at the end of the comments for #9227, I took an initial stab at adding support for function level statics and decided it would be enough work to warrant being split into a separate issue.

See #13144 for the new issue describing the need to add support for function level static variables.
Added two simd expressions:
 * ExprSimd - SIMD gather
 * ExprSwizzle - Two operand shuffle
Added ty_simd and a corresponding ty_infer type.
Added simd_syntax for accessing the new expressions as well as a
new crate providing basic multiple-data types and implementations.
```make install``` needs dylib output.
Rebasing fallout.
Add missing digit in resolve.
Rebase fallout.
Added smearing, aka splat or broadcast.
Multiple-data statics.
Rebase fallout.