port util/common.rs from oldvisit to <V:Visitor> trait API.
Ported coherence.rs from oldvisit to <V:Visitor> trait API.
Ported rusti::utils from oldvisit to <V:Visitor> trait API.
Port entry.rs from oldvisit to <V:Visitor> trait API.
Port freevars.rs from oldvisit to <V:Visitor> trait.
Port kind.rs from oldvisit to <V:Visitor> trait API.
ported lang_items from oldvisit to <V:Visitor> trait.
Port check_loans.rs from oldvisit to <V:Visitor> trait API.
Revert "Turn off jemalloc"

This reverts commit 371a316ec93a977f9dcd305b5f532cd394fa6885.

Closes #7217
auto merge of #8623 : pnkfelix/rust/fsk-visitor-vpar-defaults-step4, r=nmatsakis

Follow up to #8619 (step 3 of 5).

(See #8527, which was step 1 of 5, for the full outline.)

Part of #7081.
test: un-xfail now working run-pass/foreign-struct.rs, close #2334.
test: add testcase, close #4929 which was already fixed.
Add tests for cross-crate condition handling. Close #5446.
Try to fix mac valgrind bot by disabling thread-heavy activities.
compiletest: do not run tests in sub-threads if on valgrind.
rustpkg: Un-ignore most of the remaining tests

This necessitated some cleanup to how we parse library filenames
when searching for libraries, since rustpkg may now create filenames
that contain '-' characters. Also cleaned up how rustpkg passes the
sysroot to a custom build script.
rt: make jemalloc header conform to android signature.
auto merge of #8500 : graydon/rust/2013-08-13-self-rollup, r=thestinger

close #8424 r=brson
close #8173 r=brson
close #8209 r=strcat
regenerate configure
jemalloc: use $(AR), not `ar`