Switch to clang-r339409.

This also changes over llvm-strip to use the -o flag, rather than
relying on nonstandard (and no longer functional) positional arguments.

Bug: http://b/111998531
Test: Multiple new builds. For googlers - http://go/clang-r339409-testing
Change-Id: I8c82d06304af24a001e6552e36e2f540d8e364ce
diff --git a/cc/config/global.go b/cc/config/global.go
index 000aab6..ad63c97 100644
--- a/cc/config/global.go
+++ b/cc/config/global.go
@@ -126,8 +126,8 @@
 
 	// prebuilts/clang default settings.
 	ClangDefaultBase         = "prebuilts/clang/host"
-	ClangDefaultVersion      = "clang-r328903"
-	ClangDefaultShortVersion = "7.0.2"
+	ClangDefaultVersion      = "clang-r339409"
+	ClangDefaultShortVersion = "8.0.1"
 
 	// Directories with warnings from Android.bp files.
 	WarningAllowedProjects = []string{