Post-reset bootmgr's phantom no-RAM

Post-reset Longhorn builds (roughly 5048 through early 5308) often die on modern hardware with BlInitializeLibrary failed 0xc0000017 — STATUS_NO_MEMORY — even when the machine clearly has RAM to spare. The message is misleading; the real story is stranger. Here&rsquo;s how that was chased down, and a small patch for bootmgr / winload.exe that fixes it.