[gn] Fix config for using clang

infra/mb/mb_config.pyl

 # Copyright 2016 The V8 project authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 {
   # This is a map of buildbot master names -> buildbot builder names ->
   # config names (where each config name is a key in the 'configs' dict,
   # below). MB uses this dict to look up which config to use for a given bot.
   # Bots are ordered by appearance on waterfall.
   'masters': {
@@ skipping 354 matching lines @@
       'gn_args': 'target_cpu="arm"',
       'gyp_defines': 'target_arch=arm',
     },
 
     'arm64': {
       'gn_args': 'target_cpu="arm64"',
       'gyp_defines': 'target_arch=arm64',
     },
 
     'asan': {
-      'gn_args': 'clang=true asan=true',
+      'gn_args': 'is_clang=true asan=true',
       'gyp_defines': 'clang=1 asan=1',
     },
 
     'bb': {
       'gn_args': 'sanitizer_coverage_flags="bb"',
       'gyp_defines': 'sanitizer_coverage=bb',
     },
 
     'cfi': {
       'gn_args': 'is_cfi=true use_cfi_diag=true',
       'gyp_defines': 'cfi_vptr=1 cfi_diag=1',
     },
 
     'clang': {
-      'gn_args': 'clang=true',
+      'gn_args': 'is_clang=true',
       'gyp_defines': 'clang=1',
     },
 
     'coverage': {
       # TODO(machenbach): Add this to gn.
       'gyp_defines': 'coverage=1',
     },
 
     'crosscompile': {
       'gyp_crosscompile': True,
@@ skipping 17 matching lines @@
     'debug_trybot': {
       'mixins': ['debug_bot', 'minimal_symbols'],
     },
 
     'edge': {
       'gn_args': 'sanitizer_coverage_flags="edge"',
       'gyp_defines': 'sanitizer_coverage=edge',
     },
 
     'gcc': {
-      'gn_args': 'clang=false',
+      'gn_args': 'is_clang=false',
       'gyp_defines': 'clang=0',
     },
 
     'gcmole': {
       'gn_args': 'v8_gcmole=true',
       'gyp_defines': 'gcmole=1',
     },
 
     'gn': {'type': 'gn'},
 
@@ skipping 20 matching lines @@
       'gn_args': 'symbol_level=1',
       'gyp_defines': 'fastbuild=1',
     },
 
     'mips': {
       'gn_args': 'target_cpu="mips"',
       'gyp_defines': 'target_arch=mips',
     },
 
     'msan': {
-      'gn_args': 'clang=true msan=true',
+      'gn_args': 'is_clang=true msan=true',
       'gyp_defines': 'clang=1 msan=1',
     },
 
     'release': {
       'gn_args': 'is_debug=false',
     },
 
     'release_bot': {
       'mixins': ['release', 'static', 'goma'],
     },
@@ skipping 63 matching lines @@
     },
 
     # TODO(machenbach): Remove the symbolized config after the bots are  gone.
     'symbolized': {
       'gn_args': 'symbolized=true',
       'gyp_defines':
         'release_extra_cflags="-fno-inline-functions -fno-inline"',
     },
 
     'tsan': {
-      'gn_args': 'clang=true tsan=true',
+      'gn_args': 'is_clang=true tsan=true',
       'gyp_defines': 'clang=1 tsan=1',
     },
 
     'valgrind': {
       'gn_args': 'v8_has_valgrind=true',
       'gyp_defines': 'has_valgrind=1',
     },
 
     'v8_no_i18n': {
       'gn_args': 'v8_enable_i18n_support=false',
@@ skipping 62 matching lines @@
       'gn_args': 'target_cpu="x64"',
       'gyp_defines': 'target_arch=x64',
     },
 
     'x86': {
       'gn_args': 'target_cpu="x86"',
       'gyp_defines': 'target_arch=ia32',
     },
   },
 }