Resource operations (e.g. mju_openResource, mju_readResource, and
mju_closeResource, etc.) are now all handled by a VFS instance. It
is now up to the VFS to determine which provider to use in order to
handle those operations.
This allows us to dynamically add/remove (aka "mount") providers to
a VFS to handle special requests. mj_addFileVFS and mj_addBufferVFS
have been reimplemented as two such use-cases. Moreover, we expose
the mounting behaviour with two new functions: mj_mountVFS and
mj_unmountVFS.
PiperOrigin-RevId: 863248779
Change-Id: I8bcbd5445814ba1e72c6d7b80ad6a054f5f1df57
Haroon Qureshi
b073cd2ca4