build: add --enable-d8 configure option

Add an option to the configure script for building d8.  Useful for
testing V8 standalone.

PR-URL: https://github.com/nodejs/node/pull/7538
Reviewed-By: Anna Henningsen <[email protected]>
Reviewed-By: James M Snell <[email protected]>
Reviewed-By: Rod Vagg <[email protected]>
diff --git a/node.gyp b/node.gyp
index f84de39..8a8bd00 100644
--- a/node.gyp
+++ b/node.gyp
@@ -248,6 +248,9 @@
             }]
           ],
         }],
+        [ 'node_enable_d8=="true"', {
+          'dependencies': [ 'deps/v8/src/d8.gyp:d8' ],
+        }],
         [ 'node_use_bundled_v8=="true"', {
           'dependencies': [
             'deps/v8/tools/gyp/v8.gyp:v8',