Switch to clang-r344140b

Bug: http://b/119270185

This prebuilt has a cherry-pick to fix PGO instrumentation.

Test: m ANDROID_PGO_INSTRUMENT=all,
      Build and boot a few devices in internal branch.
Change-Id: I97ca17fbc039a17db57b2749a1adf2ef981c5918
diff --git a/cc/config/global.go b/cc/config/global.go
index 7cb3679..e2377e3 100644
--- a/cc/config/global.go
+++ b/cc/config/global.go
@@ -122,8 +122,8 @@
 
 	// prebuilts/clang default settings.
 	ClangDefaultBase         = "prebuilts/clang/host"
-	ClangDefaultVersion      = "clang-r344140"
-	ClangDefaultShortVersion = "8.0.3"
+	ClangDefaultVersion      = "clang-r344140b"
+	ClangDefaultShortVersion = "8.0.4"
 
 	// Directories with warnings from Android.bp files.
 	WarningAllowedProjects = []string{