[buildtools] Roll new toolchain

Change-Id: I1e8bf387832a9745a6ac579cec5797812a534de6
diff --git a/fuchsia.ensure b/fuchsia.ensure
index 193c833..9e77706 100644
--- a/fuchsia.ensure
+++ b/fuchsia.ensure
@@ -23,7 +23,7 @@
 
 # Clang
 @Subdir clang
-fuchsia/clang/${platform} git_revision:a40dc377f2f109fbe3147019ea6daec914d2587c
+fuchsia/clang/${platform} git_revision:5e388b41ff108e989f3371601691acb22d597e76
 
 # Go
 @Subdir go