emit warnings on V8 < 6.5.143 also

README.md

@@ -12,7 +12,7 @@ The extension allows you to execute Javascript code in a secure sandbox from PHP
 can be restricted using a time limit and/or memory limit. This provides the possibility to execute
 untrusted code with confidence.
 
-If you execute untrusted JavaScript code, make sure to **use V8 version 6.4.388.18 or higher**.
+If you execute untrusted JavaScript code, make sure to **use V8 version 6.4.388.18, 6.5.143 or higher**.
 See notes on [untrusted code mitigations](https://github.com/v8/v8/wiki/Untrusted-code-mitigations)
 for further details.
 

config.m4

@@ -147,6 +147,9 @@ int main ()
     if test "$V8_API_VERSION" -lt 6004388 ; then
        AC_MSG_WARN([libv8 prior to 6.4.388.18 is missing speculative execution mitigations])
     fi
+    if test "$V8_API_VERSION" -ge 6005000 -a "$V8_API_VERSION" -lt 6005143 ; then
+       AC_MSG_WARN([libv8 6.5.x prior to 6.5.143 is missing speculative execution mitigations])
+    fi
     AC_DEFINE_UNQUOTED([PHP_V8_API_VERSION], $V8_API_VERSION, [ ])
     AC_DEFINE_UNQUOTED([PHP_V8_VERSION], "$ac_cv_v8_version", [ ])
   else