allow cliloader to proceed in more cases

[bashbaug]

Description of Changes

On Windows, if the child thread to replace functions cannot be created, we should still continue, since loading the intercept layer OpenCL.dll in the child process is usually enough to successfully intercept OpenCL calls.

Testing Done

Forced the child thread to fail creation. Observed that cliloader could proceed, and that interception was successful.

[bashbaug]

Marking as draft for a bit more review and testing.

[bashbaug]

This was not as helpful as I was initially hoping it would be, but it doesn't seem to be hurting anything either.