update lld submodule to include RISCV patch

danc86 · danc86 · commit 99bba340f77a · 2018-08-19T21:26:05.000+10:00
This pulls in one new commit, to add support for linking static RISCV binaries, suitable for the new riscv32imac-unknown-none-elf target. See: rust-lang/lld#1
diff --git a/src/tools/lld b/src/tools/lld
@@ -1 +1 @@
-Subproject commit f76ea3ca16ed22dde8ef929db74a4b4df6f2f899
+Subproject commit 813b3b952c07b6b85732c3fbdf3eb74f61a9fa96
