binding.gyp.cmake: get v8 version from node and export to c++ compiler

Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>

src/javascript/binding.gyp.cmake

@@ -9,11 +9,16 @@
       'include_dirs': [
 @mraa_LIB_INCLUDE_DIRS_GYP@
                       ],
+      'variables': {
+          "v8_version%": "<!(node -e 'console.log(process.versions.v8)' | sed 's/\.//g')"
+      },
       'cflags_cc!': [ '-fno-rtti', '-fno-exceptions' ],
       'cflags!': [ '-fno-exceptions' ],
       'defines' : [ 'SWIG',
                     'SWIGJAVASCRIPT',
-		    'BUILDING_NODE_EXTENSION=1' ],
+                    'BUILDING_NODE_EXTENSION=1',
+                    'SWIG_V8_VERSION=0x0<(v8_version)',
+                    'V8_VERSION=0x0<(v8_version)' ],
       'conditions' : [
           [ 'target_arch=="x64"',
             { 'defines' : [ 'X86PLAT=ON' ], },