[Driver] Link sanitizer runtime deps on Fuchsia when needed

Even though these deps weren't needed, this makes Fuchsia driver
better match other drivers, and it may be necessary when trying to
use different C libraries on Fuchsia.

Differential Revision: https://reviews.llvm.org/D54741

llvm-svn: 347378
diff --git a/clang/lib/Driver/ToolChains/Fuchsia.cpp b/clang/lib/Driver/ToolChains/Fuchsia.cpp
index cfda9b4..c5f6caf 100644
--- a/clang/lib/Driver/ToolChains/Fuchsia.cpp
+++ b/clang/lib/Driver/ToolChains/Fuchsia.cpp
@@ -109,8 +109,7 @@
                   D.getLTOMode() == LTOK_Thin);
   }
 
-  addSanitizerRuntimes(ToolChain, Args, CmdArgs);
-
+  bool NeedSanitizerDeps = addSanitizerRuntimes(ToolChain, Args, CmdArgs);
   AddLinkerInputs(ToolChain, Inputs, Args, CmdArgs, JA);
   ToolChain.addProfileRTLibs(Args, CmdArgs);
 
@@ -134,6 +133,9 @@
       }
     }
 
+    if (NeedSanitizerDeps)
+      linkSanitizerRuntimeDeps(ToolChain, CmdArgs);
+
     AddRunTimeLibs(ToolChain, D, CmdArgs, Args);
 
     if (Args.hasArg(options::OPT_pthread) ||