[DirectX] Eliminate resource global variables from module (#114105)
By giving these intrinsics their appropriate attributes, loads of
globals that are stored on the other side of these calls can be
eliminated by the EarlyCSE pass. Stores to the same globals and the
globals themselves require more direct intervention as part of the
create/annotated handle lowering.
Adds a test that verifies that the unneeded globals and their uses can
be eliminated and also that the attributes are set properly.
Fixes #104271