gn.args:
clang_use_chrome_plugins = false
is_clang = true
is_component_build = false
is_debug = false
is_official_build = true
symbol_level = 0
target_cpu = "x86"
use_lld = true

Chromium 512925 with Clang r317031. Build and run base_unittests. 2 test failures and 4 crashing tests. If I comment out "target_cpu = \"x86\"" to get a 64-bit build, all tests pass.

2 tests failed:
    Debugger.DoesntExecuteBeyondBreakpoint (../../base/debug/debugger_unittest.cc:34)
    OutOfMemoryDeathTest.NewHandlerGeneratesUnhandledException (../../base/process/memory_unittest.cc:228)
4 tests crashed:
    LoggingTest.CheckCausesDistinctBreakpoints (../../base/logging_unittest.cc:233)
    OutOfMemoryTest.TerminateBecauseOutOfMemoryReportsAllocSize (../../base/process/memory_unittest.cc:485)
    SecurityTest.NewOverflow (../../base/security_unittest.cc:96)
    WrappedWindowProc.CatchesExceptions (../../base/win/wrapped_window_proc_unittest.cc:56)