build: ./configure pass positional args to gyp

use `--` to specify the arguments you want to pass directly to gyp.

for example: `./configure -- --no-parallel -Dsome_define=foo`

fixes #6370

configure

@@ -695,13 +695,17 @@ config = '\n'.join(map('='.join, config.iteritems())) + '\n'
 write('config.mk',
       '# Do not edit. Generated by the configure script.\n' + config)
 
+gyp_args = [sys.executable, 'tools/gyp_node.py']
+
 if options.use_ninja:
-  gyp_args = ['-f', 'ninja-' + flavor]
+  gyp_args += ['-f', 'ninja-' + flavor]
 elif options.use_xcode:
-  gyp_args = ['-f', 'xcode']
+  gyp_args += ['-f', 'xcode']
 elif flavor == 'win':
-  gyp_args = ['-f', 'msvs', '-G', 'msvs_version=auto']
+  gyp_args += ['-f', 'msvs', '-G', 'msvs_version=auto']
 else:
-  gyp_args = ['-f', 'make-' + flavor]
+  gyp_args += ['-f', 'make-' + flavor]
+
+gyp_args += args
 
-subprocess.call([sys.executable, 'tools/gyp_node.py'] + gyp_args)
+subprocess.call(gyp_args)