Bump linker to match mono/linker. Fixes #60163.

Bump our own linker submodule to match mono's (and xamarin-android's) linker submodule. Diff: 0cbb1e7871...99354bf5c1 https://bugzilla.xamarin.com/show_bug.cgi?id=60163
2017-10-16 12:33:09 +02:00 · 2017-10-16 12:33:09 +02:00 · 702d108c31
--- a/external/linker
+++ b/external/linker
@ -1 +1 @@
-Subproject commit 0cbb1e787172bdfd8b2964f683d979e0ba719b41
+Subproject commit 99354bf5c13b8055209cb082cddc50c8047ab088