[3.14] gh-127146: Emscripten: Fix pathlib glob_dotdot test (GH-135624) (#135653)

[3.14] gh-127146: Emscripten: Fix pathlib glob_dotdot test (GH-135624) (#135653)

The Emscripten path resolver uses the same mechanism for resolving `..`
at a file system root as for resolving symlinks. This is because
roots don't store their mountpoints. If the parent of a node is itself,
it is a root but it might be a mountpoint in some other file system.

If a path has enough `..`'s at the root, it will return ELOOP.
Enough turns out to be 49.
(cherry picked from commit e4ccd46bf75fff2938d7c21c7284e49b0ab795b0)

Co-authored-by: Hood Chatham <roberthoodchatham@gmail.com>