Restore LLVM to the correct revision

lilyball · lilyball · commit e61c7fd3e20d · 2014-02-21T23:59:58.000-08:00
PR rust-lang#12407 was accidentally reverted by PR rust-lang#12411. Restore the correct version of LLVM that PR rust-lang#12407 introduced.
diff --git a/src/llvm b/src/llvm
@@ -1 +1 @@
-Subproject commit f5f1ffea207b6b380127ff34f14015ae005d1413
+Subproject commit b015ecddd3129490fa26e5278a1acee79f2ee5ef
