libc++: Disable exceptions and RTTI

Except on Mac, where exceptions are required.
And except on Android, where rtti is required.

src/buildtools/third_party/libc++/BUILD.gn

@@ -114,14 +114,10 @@ builtin_modules("_Builtin_unwind") {
 configs_to_add = [
   ":config",
   "//build/config/compiler:no_chromium_code",
-  "//build/config/compiler:exceptions",
-  "//build/config/compiler:rtti",
 ]
 
 configs_to_remove = [
   "//build/config/compiler:chromium_code",
-  "//build/config/compiler:no_exceptions",
-  "//build/config/compiler:no_rtti",
   "//build/config/coverage:default_coverage",
 ]
 

src/buildtools/third_party/libc++abi/BUILD.gn

@@ -102,4 +102,34 @@ target(libcxxabi_target_type, "libc++abi") {
   if (use_libcxx_modules) {
     configs -= [ "//build/config/compiler:libcxx_module" ]
   }
+  if (!is_apple) {
+    sources -= [
+      "//third_party/libc++abi/src/src/cxa_exception.cpp",
+      "//third_party/libc++abi/src/src/cxa_personality.cpp",
+      "//third_party/libc++abi/src/src/private_typeinfo.cpp",
+    ]
+    sources += [
+      "//third_party/libc++abi/src/src/cxa_noexception.cpp",
+    ]
+    defines += [ "_LIBCXXABI_NO_EXCEPTIONS" ]
+    configs -= [
+      "//build/config/compiler:exceptions",
+      "//build/config/compiler:rtti",
+    ]
+    configs += [
+      "//build/config/compiler:no_exceptions",
+      "//build/config/compiler:no_rtti",
+    ]
+  }
+  if (is_android) {
+    sources += [
+      "//third_party/libc++abi/src/src/private_typeinfo.cpp",
+    ]
+    configs -= [
+      "//build/config/compiler:no_rtti",
+    ]
+    configs += [
+      "//build/config/compiler:rtti",
+    ]
+  }
 }