Loading Renderdoc Wrong

[cwfitzgerald]

Description

See #2789 for original issue.

We aren't properly loading renderdoc. We are missing some flags that needs to be passed to dlopen to make sure we never actually load renderdoc's ourselves we only pull the existing copy.

See the documentation here for more info: https://renderdoc.org/docs/in_application_api.html

The important bit:

To do this you’ll use your platforms dynamic library functions to see if the library is open already - e.g. GetModuleHandle on Windows, or dlopen with the RTLD_NOW | RTLD_NOLOAD flags if available on *nix systems. On most platforms you can just search for the module name - renderdoc.dll on Windows, or librenderdoc.so on Linux, or libVkLayer_GLES_RenderDoc.so on Android should be sufficient here, so you don’t need to know the path to where RenderDoc is running from.

In libloading terms:

On windows this should call https://docs.rs/libloading/latest/libloading/os/windows/struct.Library.html#method.open_already_loaded which is GetModuleHandle.

On linux this should call https://docs.rs/libloading/latest/libloading/os/unix/struct.Library.html#method.open with RTLD_NOW | RTLD_NOLOAD - the latter needs to be added to lib loading, but it's just an integer so we can just specify the value until lib loading adds it.