Rollup merge of #33698 - alexcrichton:update-libc, r=japaric

Manishearth · Manishearth · commit 26f666b7ad59 · 2016-05-19T21:21:06.000+05:30
std: Update libc submodule Brings in a fix where `-lutil` is no longer passed for musl targets, lifting the need for a musl toolchain to be installed again. Closes #33608
diff --git a/src/liblibc b/src/liblibc
@@ -1 +1 @@
-Subproject commit 6598e2cbfd7e09bfca249cc3dcbf889735f73ce1
+Subproject commit b19b5465a1235be3323363cdc11838739b593029
