Disable assembly optimizations in MemorySanitizer builds of libjpeg_turbo.

libjpeg.gyp

 # Copyright (c) 2012 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.
 
 {
   # This file is not used when use_system_libjepg==1. Settings for building with
   # the system libjpeg is in third_party/libjpeg/libjpeg.gyp.
   'variables': {
     'shared_generated_dir': '<(SHARED_INTERMEDIATE_DIR)/third_party/libjpeg_turbo',
     'conditions': [
@@ skipping 118 matching lines @@
             'simd/jimmxint.asm',
             'simd/jimmxred.asm',
             'simd/jiss2flt.asm',
             'simd/jiss2fst.asm',
             'simd/jiss2int.asm',
             'simd/jiss2red.asm',
             'simd/jisseflt.asm',
             'simd/jsimdcpu.asm',
           ],
         }],
-        [ 'target_arch=="x64"', {
+        [ 'target_arch=="x64" and msan!=1', {
           'sources': [
             'simd/jsimd_x86_64.c',
             'simd/jccolss2-64.asm',
             'simd/jcgrass2-64.asm',
             'simd/jcqnts2f-64.asm',
             'simd/jcqnts2i-64.asm',
             'simd/jcsamss2-64.asm',
             'simd/jdcolss2-64.asm',
             'simd/jdmerss2-64.asm',
             'simd/jdsamss2-64.asm',
             'simd/jfss2fst-64.asm',
             'simd/jfss2int-64.asm',
             'simd/jfsseflt-64.asm',
             'simd/jiss2flt-64.asm',
             'simd/jiss2fst-64.asm',
             'simd/jiss2int-64.asm',
             'simd/jiss2red-64.asm',
           ],
         }],
+        # MemorySanitizer doesn't support assembly code, so keep it disabled in
+        # MSan builds for now.
+        [ 'msan==1', {
+          'sources': [
+            'jsimd_none.c',
+          ],
+        }],
         # The ARM SIMD implementation can be used for devices that support
         # the NEON instruction set. This can safely be done dynamically by
         # probing CPU features at runtime, if you wish.
         [ 'target_arch=="arm"', {
           'conditions': [
             [ 'arm_version >= 7 and (arm_neon == 1 or arm_neon_optional == 1)', {
               'sources': [
                 'simd/jsimd_arm.c',
                 'simd/jsimd_arm_neon.S',
               ],
@@ skipping 126 matching lines @@
       ],
     },
   ],
 }
 
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