Merge changes from topic 'genrule-multi-out'

* changes:
  Remove shared lib name checks
  Add export_generated_headers
  Support multiple outputs for genrule
  Parse genrule's cmd property
  Expose HostToolPath on the cc module to fix genrule.tool
diff --git a/cc/config/global.go b/cc/config/global.go
index d17a7d1..0a7bdc5 100644
--- a/cc/config/global.go
+++ b/cc/config/global.go
@@ -124,7 +124,7 @@
 		if override := config.(android.Config).Getenv("LLVM_PREBUILTS_VERSION"); override != "" {
 			return override, nil
 		}
-		return "clang-3217047", nil
+		return "clang-3289846", nil
 	})
 	pctx.StaticVariable("ClangPath", "${ClangBase}/${HostPrebuiltTag}/${ClangVersion}")
 	pctx.StaticVariable("ClangBin", "${ClangPath}/bin")