[GN]: Add asmflags

tools/gn/function_toolchain.cc

 // 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.
 
 #include <algorithm>
 #include <limits>
 
 #include "tools/gn/err.h"
 #include "tools/gn/functions.h"
 #include "tools/gn/parse_tree.h"
@@ skipping 600 matching lines @@
     "        The short name of the current target with no path information,\n"
     "        or the value of the \"output_name\" variable if one is specified\n"
     "        in the target. This will include the \"output_prefix\" if any.\n"
     "        Example: \"libfoo\" for the target named \"foo\" and an\n"
     "        output prefix for the linker tool of \"lib\".\n"
     "\n"
     "  Compiler tools have the notion of a single input and a single output,\n"
     "  along with a set of compiler-specific flags. The following expansions\n"
     "  are available:\n"
     "\n"
+    "    {{asmflags}}\n"
     "    {{cflags}}\n"
     "    {{cflags_c}}\n"
     "    {{cflags_cc}}\n"
     "    {{cflags_objc}}\n"
     "    {{cflags_objcc}}\n"
     "    {{defines}}\n"
     "    {{include_dirs}}\n"
     "        Strings correspond that to the processed flags/defines/include\n"
     "        directories specified for the target.\n"
     "        Example: \"--enable-foo --enable-bar\"\n"
@@ skipping 323 matching lines @@
     return Value();
 
   Scope::KeyValueMap values;
   block_scope.GetCurrentScopeValues(&values);
   toolchain->args() = values;
 
   return Value();
 }
 
 }  // namespace functions