[lldb/test] Stop recording fundamental return types (NFC)

It seems that recording fundamental return type is bogus.

This can trigger asserts when running a test with reproducers so this
patch updates the `SBTarget::IsLoaded` test to stop recording them.

Differential Revision: https://reviews.llvm.org/D95686



Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>