Sync patches r14454, r14455, r14456, r14457, r14458, and r14462 from main trunk.
1. MdeModulePkg: Variable drivers robustly handle crashes during Reclaim().
2. SecurityPkg: Variable drivers robustly handle crashes during Reclaim().
3. Nt32Pkg: Use FaultTolerantWritePei driver.
4. EmulatorPkg: Use FaultTolerantWritePei driver.
5. OvmfPkg EmuVariableFvbRuntimeDxe: Let FaultTolerantWriteDxe to init working block header.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <jeff.fan@intel.com>

git-svn-id: svn://svn.code.sf.net/p/edk2/code/branches/UDK2010.SR1/OvmfPkg@15341 6f19259b-4bc3-4df7-8a09-765794883524