regexp-generator: Include these generated tests in make.py

This is necessary so that updates to the tests without corresponding
updates to the generator script will be flagged in CI runs.

make.py

@@ -10,8 +10,10 @@
 UPSTREAM = os.environ.get('UPSTREAM') or '[email protected]:tc39/test262.git'
 MAINTAINER = os.environ.get('MAINTAINER') or '[email protected]'
 
-def shell(*args):
-    sp = subprocess.Popen(list(args), stdout=subprocess.PIPE, universal_newlines=True)
+
+def shell(*args, **kwargs):
+    sp = subprocess.Popen(list(args), stdout=subprocess.PIPE,
+                          universal_newlines=True, **kwargs)
     cmd_str = ' '.join(args)
 
     print('> ' + cmd_str)
@@ -38,17 +40,27 @@ def wrapped():
         return wrapped
     return other
 
+
 @target()
+def npm_deps():
+    shell('npm', 'install', cwd='./tools/regexp-generator')
+
+
+@target('npm_deps')
 def build():
     shell(sys.executable, 'tools/generation/generator.py',
           'create',
           '--parents',
           '--out', OUT_DIR,
           SRC_DIR)
+    shell('npm', 'run', 'build', cwd='./tools/regexp-generator')
 
-@target()
+
+@target('npm_deps')
 def clean():
     shell(sys.executable, 'tools/generation/generator.py', 'clean', OUT_DIR)
+    shell('npm', 'run', 'clean', cwd='./tools/regexp-generator')
+
 
 @target('clean', 'build')
 def deploy():