debuginfo: Improved stepping for if-expressions
Don't mark reachable extern fns as internal

If a function is marked as external, then it's likely desired for use with some
native library, so we're not really accomplishing a whole lot by internalizing
all of these symbols.
auto merge of #10539 : alexcrichton/rust/external-linkage, r=pcwalton

If a function is marked as external, then it's likely desired for use with some
native library, so we're not really accomplishing a whole lot by internalizing
all of these symbols.
pidigits resurected

Changes:
* default value when no args
* license
* removed libc printing
* use extra::bigint instead of handmade gmp binding
auto merge of #10555 : TeXitoi/rust/pidigits-resurected, r=alexcrichton

Changes:
* default value when no args
* license
* removed libc printing
* use extra::bigint instead of handmade gmp binding

The drawback is that it's 2 order of magnitude slower, the good news is that there is a good bench for extra::bigint.
auto merge of #10552 : michaelwoerister/rust/ifstepping, r=brson

This PR improves the single-stepping experience for if-expression (no more jumping into the *else* branch before entering the *then* branch, no more jumping to the end of the *else* branch after finishing the *then* branch). Unfortunately I don't know of a straight-forward way of writing automated tests for this. Suggestions welcome!
Use '..' as multi-field wildcard in enums and structs.
Use '..' as slice wildcard in vectors
auto merge of #10366 : brson/rust/ignore-patterns, r=alexcrichton

This replaces `*` with `..` in enums, `_` with `..` in structs, and `.._` with `..` in vectors. It adds obsolete syntax warnings for the old forms but doesn't turn them on yet because we need a snapshot.

#5830
Map trait improvements
Only store the last inserted key in smallintmap

Instead of associating a redundant key with each value, so find_or_insert_with
can keep a reference to it, just store the one that was just inserted.
Merge https://github.com/davidhalperin/rust

Conflicts:
	src/libextra/smallintmap.rs