[Arm]: Simplify compile-time Arm feature detection.

src/flag-definitions.h

 // Copyright 2012 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 file defines all of the flags.  It is separated into different section,
 // for Debug, Release, Logging and Profiling, etc.  To add a new flag, find the
 // correct section, and use one of the DEFINE_ macros, without a trailing ';'.
 //
 // This include does not have a guard, because it is a template-style include,
 // which can be included multiple times in different modes.  It expects to have
@@ skipping 87 matching lines @@
     MaybeBoolFlag flag;
     flag.has_value = has_value;
     flag.value = value;
     return flag;
   }
   bool has_value;
   bool value;
 };
 #endif
 
-#if (defined CAN_USE_VFP3_INSTRUCTIONS) || !(defined ARM_TEST)
+#if (defined CAN_USE_VFP3_INSTRUCTIONS) || !(defined ARM_TEST_NO_FEATURE_PROBE)
 # define ENABLE_VFP3_DEFAULT true
 #else
 # define ENABLE_VFP3_DEFAULT false
 #endif
-#if (defined CAN_USE_ARMV7_INSTRUCTIONS) || !(defined ARM_TEST)
+#if (defined CAN_USE_ARMV7_INSTRUCTIONS) || !(defined ARM_TEST_NO_FEATURE_PROBE)
 # define ENABLE_ARMV7_DEFAULT true
 #else
 # define ENABLE_ARMV7_DEFAULT false
 #endif
-#if (defined CAN_USE_VFP32DREGS) || !(defined ARM_TEST)
+#if (defined CAN_USE_VFP32DREGS) || !(defined ARM_TEST_NO_FEATURE_PROBE)
 # define ENABLE_32DREGS_DEFAULT true
 #else
 # define ENABLE_32DREGS_DEFAULT false
 #endif
-#if (defined CAN_USE_NEON) || !(defined ARM_TEST)
+#if (defined CAN_USE_NEON) || !(defined ARM_TEST_NO_FEATURE_PROBE)
 # define ENABLE_NEON_DEFAULT true
 #else
 # define ENABLE_NEON_DEFAULT false
 #endif
 
 #define DEFINE_bool(nam, def, cmt)   FLAG(BOOL, bool, nam, def, cmt)
 #define DEFINE_maybe_bool(nam, cmt)  FLAG(MAYBE_BOOL, MaybeBoolFlag, nam,  \
                                           { false COMMA false }, cmt)
 #define DEFINE_int(nam, def, cmt)    FLAG(INT, int, nam, def, cmt)
 #define DEFINE_float(nam, def, cmt)  FLAG(FLOAT, double, nam, def, cmt)
@@ skipping 762 matching lines @@
 #undef DEFINE_ALIAS_float
 #undef DEFINE_ALIAS_args
 
 #undef FLAG_MODE_DECLARE
 #undef FLAG_MODE_DEFINE
 #undef FLAG_MODE_DEFINE_DEFAULTS
 #undef FLAG_MODE_META
 #undef FLAG_MODE_DEFINE_IMPLICATIONS
 
 #undef COMMA