(Really) disable gdb-index for LTO.

build/config/compiler/BUILD.gn

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/android/config.gni")
 import("//build/config/chrome_build.gni")
 import("//build/config/chromecast_build.gni")
 import("//build/config/compiler/compiler.gni")
 import("//build/config/nacl/config.gni")
 import("//build/toolchain/cc_wrapper.gni")
@@ skipping 1643 matching lines @@
     # TODO(thakis): Figure out if there's a way to make this go for 32-bit,
     # currently we get "warning:
     # obj/native_client/src/trusted/service_runtime/sel_asm/nacl_switch_32.o:
     # DWARF info may be corrupt; offsets in a range list entry are in different
     # sections" there.  Maybe just a bug in nacl_switch_32.S.
     # TODO(thakis): Figure out if there's a way to make this go for official
     # builds, currently get
     # "third_party/binutils/Linux_x64/Release/bin/ld.gold: warning:
     # /tmp/lto-llvm-0b5201.o: corrupt debug info in .debug_info"
     if (!is_mac && !is_ios && !is_nacl && target_cpu != "x86" &&
-        !is_official_build) {
+        !allow_posix_link_time_opt && !is_official_build) {
       ldflags += [ "-Wl,--gdb-index" ]
     }
   }
 }
 
 # Minimal symbols.
 config("minimal_symbols") {
   if (is_win) {
     # Linker symbols for backtraces only.
     cflags = []
@@ skipping 40 matching lines @@
 
 if (is_ios || is_mac) {
   # On Mac and iOS, this enables support for ARC (automatic ref-counting).
   # See http://clang.llvm.org/docs/AutomaticReferenceCounting.html.
   config("enable_arc") {
     common_flags = [ "-fobjc-arc" ]
     cflags_objc = common_flags
     cflags_objcc = common_flags
   }
 }