Revert of Implement arflags in the GN build. (patchset #2 id:20001 of...

Revert of Implement arflags in the GN build. (patchset #2 id:20001 of https://codereview.chromium.org/1896163003/ )

Reason for revert:
variety of compile failures on Android bots that have been switched to GN, see https://codereview.chromium.org/1896163003/#msg18

Original issue's description:
> Implement arflags in the GN build.
>
> This flag was recently added in GN. This patch hooks it up to the toolchains
> and moves some flags to use it that previously had to be hardcoded on the
> tool command itself.
>
> Remove concurrent_links variable from gcc_toolchain which was unused.
>
> BUG=598599

TBR=brucedawson@chromium.org,brettw@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=598599

Review URL: https://codereview.chromium.org/1903363003

Cr-Commit-Position: refs/heads/master@{#388646}

build/config/compiler/BUILD.gn

@@ -431,12 +431,6 @@ config("compiler") {
       ldflags += [ "-Wl,-plugin-opt,-function-sections" ]
     }
 
-    arflags = [
-      "--plugin",
-      rebase_path("//third_party/llvm-build/Release+Asserts/lib/LLVMgold.so",
-                  root_build_dir),
-    ]
-
     # TODO(pcc): Make these flags work correctly with CFI.
     if (!is_cfi) {
       cflags += [

build/config/win/BUILD.gn

@@ -103,18 +103,6 @@ config("compiler") {
     assert(!is_win_fastlink, "/PROFILE and /DEBUG:FASTLINK are incompatible")
     ldflags = [ "/PROFILE" ]
   }
-
-  # arflags apply only to static_libraries. The normal linker configs are only
-  # set for executable and shared library targets so arflags must be set
-  # elsewhere. Since this is relatively contained, we just apply them in this
-  # more general config and they will only have an effect on static libraries.
-  arflags = [
-    # "No public symbols found; archive member will be inaccessible." This
-    # means that one or more object files in the library can never be
-    # pulled in to targets that link to this library. It's just a warning that
-    # the source file is a no-op.
-    "/ignore:4221",
-  ]
 }
 
 config("vs_code_analysis") {

build/toolchain/gcc_toolchain.gni

@@ -8,6 +8,14 @@ import("//build/toolchain/cc_wrapper.gni")
 import("//build/toolchain/goma.gni")
 import("//build/toolchain/toolchain.gni")
 
+# This value will be inherited in the toolchain below.
+if (allow_posix_link_time_opt || is_cfi) {
+  concurrent_links =
+      exec_script("get_concurrent_links.py", [ "--lto" ], "value")
+} else {
+  concurrent_links = exec_script("get_concurrent_links.py", [], "value")
+}
+
 # This template defines a toolchain for something that works like gcc
 # (including clang).
 #
@@ -208,13 +216,21 @@ template("gcc_toolchain") {
 
     tool("alink") {
       rspfile = "{{output}}.rsp"
+      arflags = ""
+      if ((allow_posix_link_time_opt || is_cfi) &&
+          invoker.toolchain_os != "nacl") {
+        gold_plugin_path = rebase_path(
+                "//third_party/llvm-build/Release+Asserts/lib/LLVMgold.so",
+                root_build_dir)
+        arflags = "--plugin \"$gold_plugin_path\""
+      }
 
       # This needs a Python script to avoid using simple sh features in this
       # command, in case the host does not use a POSIX shell (e.g. compiling
       # POSIX-like toolchains such as NaCl on Windows).
       ar_wrapper =
           rebase_path("//build/toolchain/gcc_ar_wrapper.py", root_build_dir)
-      command = "$python_path \"$ar_wrapper\" --output={{output}} --ar=\"$ar\" {{arflags}} rcsD @\"$rspfile\""
+      command = "$python_path \"$ar_wrapper\" --output={{output}} --ar=\"$ar\" $arflags rcsD @\"$rspfile\""
       description = "AR {{output}}"
       rspfile_content = "{{inputs}}"
       outputs = [

build/toolchain/mac/BUILD.gn

@@ -111,7 +111,7 @@ template("mac_toolchain") {
     }
 
     tool("alink") {
-      command = "rm -f {{output}} && ./gyp-mac-tool filter-libtool libtool -static {{arflags}} -o {{output}} {{inputs}}"
+      command = "rm -f {{output}} && ./gyp-mac-tool filter-libtool libtool -static -o {{output}} {{inputs}}"
       description = "LIBTOOL-STATIC {{output}}"
       outputs = [
         "{{output_dir}}/{{target_output_name}}{{output_extension}}",

build/toolchain/win/BUILD.gn

@@ -145,7 +145,7 @@ template("msvc_toolchain") {
 
     tool("alink") {
       rspfile = "{{output}}.rsp"
-      command = "$python_path gyp-win-tool link-wrapper $env False $lib /nologo {{arflags}} /OUT:{{output}} @$rspfile"
+      command = "$python_path gyp-win-tool link-wrapper $env False $lib /nologo /ignore:4221 /OUT:{{output}} @$rspfile"
       description = "LIB {{output}}"
       outputs = [
         # Ignore {{output_extension}} and always use .lib, there's no reason to