Building chromium with ToT clang fails with the following gn args:
is_official_build = true
is_debug = false
use_gnome_keyring=false
enable_nacl = false
use_cfi_icall = false
is_cfi = false

The error is
*** Inconsistent CFA register and/or offset between pred and succ ***
Pred:  outgoing CFA Reg:6
Pred:  outgoing CFA Offset:16
Succ:  incoming CFA Reg:7
Succ:  incoming CFA Offset:8
LLVM ERROR: Found 1 in/out CFI information errors.

when linking font_service.service. The bug stems from https://reviews.llvm.org/D42848 and has been reported to the developers on llvm-commits http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20180430/547569.html