Switch to clang-r346389c.

This cherry-pick update picks up a few patches to improve hwasan, ELF
tls, and LLD for kernel builds.

Bug: http://b/122549771
Test: make checkbuild, boot
Change-Id: I8a90282af41ad4c74df819484ba2c3507e20100f
diff --git a/cc/config/global.go b/cc/config/global.go
index 13ad27c..5d98d67 100644
--- a/cc/config/global.go
+++ b/cc/config/global.go
@@ -120,8 +120,8 @@
 
 	// prebuilts/clang default settings.
 	ClangDefaultBase         = "prebuilts/clang/host"
-	ClangDefaultVersion      = "clang-r346389b"
-	ClangDefaultShortVersion = "8.0.6"
+	ClangDefaultVersion      = "clang-r346389c"
+	ClangDefaultShortVersion = "8.0.7"
 
 	// Directories with warnings from Android.bp files.
 	WarningAllowedProjects = []string{