[Driver] Link sanitizer runtime deps on Fuchsia when needed

[phosek]

Summary

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.

lib/Driver/ToolChains/Fuchsia.cpp

void fuchsia::Linker::ConstructJob(Compilation &C, const JobAction &JA,
   ToolChain.AddFilePathLibArgs(Args, CmdArgs);
 
   if (D.isUsingLTO()) {
     assert(!Inputs.empty() && "Must have at least one input.");
     AddGoldPlugin(ToolChain, Args, CmdArgs, Output, Inputs[0],
                   D.getLTOMode() == LTOK_Thin);
   }
 
-  addSanitizerRuntimes(ToolChain, Args, CmdArgs);
-
+  bool NeedSanitizerDeps = addSanitizerRuntimes(ToolChain, Args, CmdArgs);
   AddLinkerInputs(ToolChain, Inputs, Args, CmdArgs, JA);
   ToolChain.addProfileRTLibs(Args, CmdArgs);
 
   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs)) {
     if (Args.hasArg(options::OPT_static))
       CmdArgs.push_back("-Bdynamic");
 
     if (D.CCCIsCXX()) {
       if (ToolChain.ShouldLinkCXXStdlib(Args)) {
         bool OnlyLibstdcxxStatic = Args.hasArg(options::OPT_static_libstdcxx) &&
                                    !Args.hasArg(options::OPT_static);
         CmdArgs.push_back("--push-state");
         CmdArgs.push_back("--as-needed");
         if (OnlyLibstdcxxStatic)
           CmdArgs.push_back("-Bstatic");
         ToolChain.AddCXXStdlibLibArgs(Args, CmdArgs);
         if (OnlyLibstdcxxStatic)
           CmdArgs.push_back("-Bdynamic");
         CmdArgs.push_back("-lm");
         CmdArgs.push_back("--pop-state");
       }
     }
 
+    if (NeedSanitizerDeps)
+      linkSanitizerRuntimeDeps(ToolChain, CmdArgs);
+
     AddRunTimeLibs(ToolChain, D, CmdArgs, Args);
 
     if (Args.hasArg(options::OPT_pthread) ||
         Args.hasArg(options::OPT_pthreads))
       CmdArgs.push_back("-lpthread");
 
     if (Args.hasArg(options::OPT_fsplit_stack))
       CmdArgs.push_back("--wrap=pthread_create");