Let asan imply clang and use_allocator=none.

build/standalone.gypi

 # Copyright 2012 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 48 matching lines @@
               'host_arch%': 'ia32',
             }],
           ],
         },
         'host_arch%': '<(host_arch)',
         'target_arch%': '<(host_arch)',
       },
       'host_arch%': '<(host_arch)',
       'target_arch%': '<(target_arch)',
       'v8_target_arch%': '<(target_arch)',
+      'asan%': 0,
+      'lsan%': 0,
+      'msan%': 0,
+      'tsan%': 0,
 
       # goma settings.
       # 1 to use goma.
       # If no gomadir is set, it uses the default gomadir.
       'use_goma%': 0,
       'gomadir%': '',
       'conditions': [
         # Set default gomadir.
         ['OS=="win"', {
           'gomadir': 'c:\\goma\\goma-win',
         }, {
           'gomadir': '<!(/bin/echo -n ${HOME}/goma)',
         }],
       ],
     },
     'host_arch%': '<(host_arch)',
     'target_arch%': '<(target_arch)',
     'v8_target_arch%': '<(v8_target_arch)',
     'werror%': '-Werror',
     'use_goma%': '<(use_goma)',
     'gomadir%': '<(gomadir)',
+    'asan%': '<(asan)',
+    'lsan%': '<(lsan)',
+    'msan%': '<(msan)',
+    'tsan%': '<(tsan)',
 
     # .gyp files or targets should set v8_code to 1 if they build V8 specific
     # code, as opposed to external code.  This variable is used to control such
     # things as the set of warnings to enable, and whether warnings are treated
     # as errors.
     'v8_code%': 0,
 
     # Speeds up Debug builds:
     # 0 - Compiler optimizations off (debuggable) (default). This may
     #     be 5x slower than Release (or worse).
@@ skipping 51 matching lines @@
         (v8_target_arch!="x87")', {
         'clang%': 1,
       }, {
         'clang%': 0,
       }],
       ['host_arch!="ppc" and host_arch!="ppc64" and host_arch!="ppc64le"', {
         'host_clang%': '1',
       }, {
         'host_clang%': '0',
       }],
+      ['asan==1 or lsan==1 or msan==1 or tsan==1', {
+        'clang%': 1,
+        'use_allocator%': 'none',
+      }],
     ],
     # Default ARM variable settings.
     'arm_version%': 'default',
     'arm_fpu%': 'vfpv3',
     'arm_float_abi%': 'default',
     'arm_thumb': 'default',
 
     # Default MIPS variable settings.
     'mips_arch_variant%': 'r2',
     # Possible values fp32, fp64, fpxx.
@@ skipping 413 matching lines @@
     ['use_goma==1 and ("<(GENERATOR)"=="ninja" or clang==1)', {
       'make_global_settings': [
        ['CC_wrapper', '<(gomadir)/gomacc'],
        ['CXX_wrapper', '<(gomadir)/gomacc'],
        ['CC.host_wrapper', '<(gomadir)/gomacc'],
        ['CXX.host_wrapper', '<(gomadir)/gomacc'],
       ],
     }],
   ],
 }