Revert of build: Remove build system support for gold plugin, except under ChromeOS.

build/config/compiler/compiler.gni

Index: build/config/compiler/compiler.gni
diff --git a/build/config/compiler/compiler.gni b/build/config/compiler/compiler.gni
index 73f3bf04e61c47a856a070d03479125e7508a212..83369d944c8850513bb5b405711df779ccb0d499 100644
--- a/build/config/compiler/compiler.gni
+++ b/build/config/compiler/compiler.gni
@@ -120,14 +120,6 @@
 }
 
 declare_args() {
-  # Set to true to use lld, the LLVM linker. This flag may be used on Windows,
-  # Linux or Fuchsia.
-  use_lld = (is_win && host_os != "win") || is_fuchsia ||
-            ((allow_posix_link_time_opt || is_cfi) && target_os == "linux" &&
-             !is_chromeos && target_cpu == "x64")
-}
-
-declare_args() {
   # Whether to use the gold linker from binutils instead of lld or bfd.
   use_gold =
       (!use_lld && !(is_chromecast && is_linux &&