Generalize V8_INFINITY and make it constexpr

Since we don't support gcc 2.96-4.0 any more, we can generalize the
V8_INFINITY macro to always use std::numeric_limits<double>::infinity().
This also makes value constexpr on all systems.

R=tebbi@chromium.org

Change-Id: Ifa97dd2ee6d2c1e179c45f60a82d1ea8481e0590
Reviewed-on: https://chromium-review.googlesource.com/725733Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48694}

src/globals.h

@@ -8,6 +8,7 @@
 #include <stddef.h>
 #include <stdint.h>
 
+#include <limits>
 #include <ostream>
 
 #include "src/base/build_config.h"
@@ -41,21 +42,7 @@
 
 #endif  // V8_OS_WIN
 
-// Unfortunately, the INFINITY macro cannot be used with the '-pedantic'
-// warning flag and certain versions of GCC due to a bug:
-// http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11931
-// For now, we use the more involved template-based version from <limits>, but
-// only when compiling with GCC versions affected by the bug (2.96.x - 4.0.x)
-#if V8_CC_GNU && V8_GNUC_PREREQ(2, 96, 0) && !V8_GNUC_PREREQ(4, 1, 0)
-# include <limits>  // NOLINT
-# define V8_INFINITY std::numeric_limits<double>::infinity()
-#elif V8_LIBC_MSVCRT
-# define V8_INFINITY HUGE_VAL
-#elif V8_OS_AIX
-#define V8_INFINITY (__builtin_inff())
-#else
-# define V8_INFINITY INFINITY
-#endif
+#define V8_INFINITY std::numeric_limits<double>::infinity()
 
 namespace v8 {