[GN] Add solink_module tool on the Mac, Win, and GCC toolchains.

build/config/BUILDCONFIG.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.
 
 # =============================================================================
 # PLATFORM SELECTION
 # =============================================================================
 #
 # There are two main things to set: "os" and "cpu". The "toolchain" is the name
 # of the GN thing that encodes combinations of these things.
@@ skipping 413 matching lines @@
 }
 set_defaults("executable") {
   configs = _executable_configs
 }
 
 # Static library defaults.
 set_defaults("static_library") {
   configs = _native_compiler_configs
 }
 
-# Shared library defaults (also for components in component mode).
+# Shared library and loadable module defaults (also for components in component
+# mode).
 _shared_library_configs =
     _native_compiler_configs + [ "//build/config:default_libs" ]
 if (is_win) {
   _shared_library_configs += _windows_linker_configs
 } else if (is_mac) {
   _shared_library_configs += [ "//build/config/mac:mac_dynamic_flags" ]
 } else if (is_android) {
   # Strip native JNI exports from shared libraries by default. Binaries that
   # want this can remove this config.
   _shared_library_configs +=
       [ "//build/config/android:hide_native_jni_exports" ]
 }
 set_defaults("shared_library") {
   configs = _shared_library_configs
 }
+set_defaults("loadable_module") {
+  configs = _shared_library_configs
+}
 if (is_component_build) {
   set_defaults("component") {
     configs = _shared_library_configs
   }
 }
 
 # Source set defaults (also for components in non-component mode).
 set_defaults("source_set") {
   configs = _native_compiler_configs
 }
@@ skipping 99 matching lines @@
     forward_variables_from(invoker, "*")
 
     # All shared libraries must have the sanitizer deps to properly link in
     # asan mode (this target will be empty in other cases).
     if (!defined(deps)) {
       deps = []
     }
     deps += [ "//build/config/sanitizers:deps" ]
   }
 }