LibJS: Do not use the $ special character in file names

The dollar sign is a special character in POSIX shells and in the Ninja
build file format. If the file name contains a `$`, something goes wrong
in the escaping/unescaping of this symbol, and CMake/GCC/Clang generate
invalid dependency files where not all instances of `$` are escaped
properly. Because of this, Ninja fails to rebuild `$262Object.cpp` if
the headers included by it have changed.

Stale `$262Object.cpp.o` files have been the cause of mysterious crashes
multiple times which only go away after doing a clean build. Let's
prevent these from happening again by removing the `$` from the
filename.

Meta/Lagom/Tools/LibJSGCVerifier/src/main.py

@@ -39,10 +39,7 @@ paths = []
 for containing_path in PATHS_TO_SEARCH:
     for root, dirs, files in os.walk(userland_path / containing_path):
         for file in files:
-            # FIXME: The dollar sign in $262Object.cpp gets corrupted in compile_commands.json somehow, and
-            #        ends up as "\\$$262Object.cpp". This results in a clang error, so we just ignore the
-            #        file here
-            if file.endswith('.cpp') and not file.endswith('262Object.cpp'):
+            if file.endswith('.cpp'):
                 paths.append(Path(root) / file)