Windows driver: add more checks and comments to crash dump filter - Document HIGH_LEVEL constraints and rationale for pre-building a nonpaged scratch MDL. - Allocate contiguous scratch buffer with conservative PFN cap (0x7FFFFFFFFFF) and fall back to unlimited cap if needed. - Replace ASSERT with TC_BUG_CHECK for validation of write MDL mapping at HIGH_LEVEL. - Safely copy PFNs from prebuilt MDL into caller MDL: compute dst/src page counts, check capacity, copy exact PFNs and retarget MDL header fields (preserve MdlFlags). - Make DumpData cleanup defensive in unload path. - comments improvements for clarity and maintainability.