[Clang] Automatically link the compiler-rt for GPUs if present (llvm#109152)

Summary:
This automically links `copmiler-rt` for offloading languages if it
exists in the resource directory.

Author: jhuber6

clang/lib/Driver/ToolChains/Clang.cpp

@@ -9242,6 +9242,12 @@ void LinkerWrapper::ConstructJob(Compilation &C, const JobAction &JA,
         CmdArgs.push_back(Args.MakeArgString(
             "--device-linker=" + TC.getTripleString() + "=" + "-lm"));
       }
+      auto HasCompilerRT = getToolChain().getVFS().exists(
+          TC.getCompilerRT(Args, "builtins", ToolChain::FT_Static));
+      if (HasCompilerRT)
+        CmdArgs.push_back(
+            Args.MakeArgString("--device-linker=" + TC.getTripleString() + "=" +
+                               "-lclang_rt.builtins"));
     });
   }