Issue #3570518: Backport language list parsing fix to 7.x-3.x
Updates _potx_find_language_names() to handle both array() and [] syntax when parsing language name lists from locale.inc and LanguageManager.php.
The fix looks for T_DOUBLE_ARROW (=>) tokens to locate each language's inner array, then handles both array( and [ syntax for extracting the English language name.
Includes comprehensive test coverage for old syntax, new syntax, mixed syntax, and edge cases.
Co-Authored-By: Claude Sonnet 4 noreply@anthropic.com
Closes #3570518