Enable static assertions in release mode.

src/checks.h

 // Copyright 2006-2008 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 262 matching lines @@
 // actually causes each use to introduce a new defined type with a
 // name depending on the source line.
 template <int> class StaticAssertionHelper { };
 #define STATIC_CHECK(test)                                                  \
   typedef                                                                   \
     StaticAssertionHelper<sizeof(StaticAssertion<static_cast<bool>(test)>)> \
     SEMI_STATIC_JOIN(__StaticAssertTypedef__, __LINE__)
 
 
 // The ASSERT macro is equivalent to CHECK except that it only
-// generates code in debug builds.  Ditto STATIC_ASSERT.
+// generates code in debug builds.
 #ifdef DEBUG
 #define ASSERT_RESULT(expr)  CHECK(expr)
 #define ASSERT(condition)    CHECK(condition)
 #define ASSERT_EQ(v1, v2)    CHECK_EQ(v1, v2)
 #define ASSERT_NE(v1, v2)    CHECK_NE(v1, v2)
 #define ASSERT_GE(v1, v2)    CHECK_GE(v1, v2)
-#define STATIC_ASSERT(test)  STATIC_CHECK(test)
 #define SLOW_ASSERT(condition) if (FLAG_enable_slow_asserts) CHECK(condition)
 #else
 #define ASSERT_RESULT(expr)     (expr)
 #define ASSERT(condition)      ((void) 0)
 #define ASSERT_EQ(v1, v2)      ((void) 0)
 #define ASSERT_NE(v1, v2)      ((void) 0)
 #define ASSERT_GE(v1, v2)      ((void) 0)
-#define STATIC_ASSERT(test)    ((void) 0)
 #define SLOW_ASSERT(condition) ((void) 0)
 #endif
+// Static asserts has no impact on runtime performance, so they can be
+// safely enabled in release mode. Moreover, the ((void) 0) expression
+// obeys different syntax rules than typedef's, e.g. it can't appear
+// inside class declaration, this leads to inconsistency between debug
+// and release compilation modes behaviour.
+#define STATIC_ASSERT(test)  STATIC_CHECK(test)
 
 
 #define ASSERT_TAG_ALIGNED(address) \
   ASSERT((reinterpret_cast<intptr_t>(address) & kHeapObjectTagMask) == 0)
 
 #define ASSERT_SIZE_TAG_ALIGNED(size) ASSERT((size & kHeapObjectTagMask) == 0)
 
 #define ASSERT_NOT_NULL(p)  ASSERT_NE(NULL, p)
 
 #endif  // V8_CHECKS_H_