tools: allow passing absolute path of config.gypi in js2c

nodejs/node#49162

patches/node/build_add_gn_build_files.patch

@@ -2350,22 +2350,4 @@ index 11616e1bcac5308020eb68fdb811bfb86cb14dd5..845e6ce69d93983963a7a57117ecab3b
 
    if 'false' == variables.get('node_shared_libuv'):
      subdir_files('deps/uv/include', 'include/node/', action)
-diff --git a/tools/js2c.py b/tools/js2c.py
-index 54c7dfce3631001e108570b19d34966edafd624f..077bba1572f05f1aa16553894703b12abc19a985 100755
---- a/tools/js2c.py
-+++ b/tools/js2c.py
-@@ -131,6 +131,14 @@ def NormalizeFileName(filename):
-     split = split[1:]
-   if len(split):
-     filename = '/'.join(split)
-+
-+  # Electron-specific: when driving the node build from Electron, we generate
-+  # config.gypi in a separate directory and pass the absolute path to js2c.
-+  # This overrides the absolute path so that the variable names in the
-+  # generated C are as if it was in the root node directory.
-+  if filename.endswith("/config.gypi"):
-+    filename = "config.gypi"
-+
-   return os.path.splitext(filename)[0]
-
-
+