fix defines for openbsd - build fails without them:

Original version from robert@openbsd.org with modification from myself

BUG=

Review URL: https://codereview.chromium.org/856553002

Cr-Commit-Position: refs/heads/master@{#26089}

src/base/macros.h

@@ -333,7 +333,7 @@ inline void USE(T) { }
 # define V8_INTPTR_C(x)   (x ## LL)
 # define V8_PTR_PREFIX    "I64"
 #elif V8_HOST_ARCH_64_BIT
-# if V8_OS_MACOSX
+# if V8_OS_MACOSX || V8_OS_OPENBSD
 #  define V8_UINT64_C(x)   (x ## ULL)
 #  define V8_INT64_C(x)    (x ## LL)
 # else