Move c++ configs from buildtools to build/config/c++ [buildtools-side change]

third_party/libc++/BUILD.gn

Index: third_party/libc++/BUILD.gn
diff --git a/third_party/libc++/BUILD.gn b/third_party/libc++/BUILD.gn
index 1297799b583cb86ff12ef9b20c3a61fb456f5d05..49a37a795eee7930c906fac8acfabf0ec5167f8a 100644
--- a/third_party/libc++/BUILD.gn
+++ b/third_party/libc++/BUILD.gn
@@ -40,47 +40,6 @@ config("config") {
     "-fPIC",
     "-fstrict-aliasing",
   ]
-  cflags_cc = [
-    "-nostdinc++",
-    "-isystem" + rebase_path("trunk/include", root_build_dir),
-    "-isystem" + rebase_path("../libc++abi/trunk/include", root_build_dir),
-    "-std=c++11",
-  ]
-  if (is_linux && current_cpu == "arm") {
-    cflags_c = [ "-isystem" +
-                 rebase_path("../libunwind/trunk/include", root_build_dir) ]
-    cflags_cc += [ "-isystem" +
-                   rebase_path("../libunwind/trunk/include", root_build_dir) ]
-  }
-}
-
-config("no_libstdcpp") {
-  # Make sure we don't link against libc++ or libstdc++.
-  ldflags = [ "-nodefaultlibs" ]
-
-  # Unfortunately, there's no way to disable linking against just
-  # libc++ (besides using clang instead of clang++); -nodefaultlibs
-  # removes all of the default libraries, so add back the ones that we
-  # need.
-  libs = [
-    "c",
-    "m",
-  ]
-
-  if (!is_mac) {
-    libs += [
-      "gcc_s",
-      "rt",
-    ]
-  }
-
-  if (is_mac && using_sanitizer) {
-    lib_dirs = [ "//third_party/llvm-build/Release+Asserts/lib/clang/$clang_version/lib/darwin" ]
-
-    if (is_asan) {
-      libs += [ "clang_rt.asan_osx_dynamic" ]
-    }
-  }
 }
 
 if (libcpp_is_static) {
@@ -127,7 +86,6 @@ target(link_target_type, "libc++") {
   ]
   configs += [
     ":config",
-    ":no_libstdcpp",
     "//build/config/compiler:no_chromium_code",
     "//build/config/compiler:rtti",
     "//build/config/sanitizers:sanitizer_options_link_helper",
@@ -138,10 +96,3 @@ target(link_target_type, "libc++") {
     "//buildtools/third_party/libc++abi",
   ]
 }
-
-group("libcxx_proxy") {
-  deps = [
-    ":libc++",
-  ]
-  public_configs = [ ":no_libstdcpp" ]
-}