Track PGXP geometry and texture depth in allocated GPU primitive buffers

runtime/tests/pgxp_test_mod_memory.cpp

@@ -0,0 +1,5 @@
+#include <cstdint>
+
+// These isolated instruction/session fixtures have no allocated mod memory.
+// The packet-shadow fixture supplies its own bounded, allocated aperture.
+extern "C" int psx_mod_gpu_dma_memory_contains(uint32_t, uint32_t) { return 0; }