UefiCpuPkg: Use Top of each AP's stack to save CpuMpData

To remove the dependency of CPU register, 4/8 byte at the top of the
stack is occupied for CpuMpData. BIST information is also taken care
here. This modification is only for PEI phase, since in DXE phase
CpuMpData is accessed via global variable.

Signed-off-by: Yuanhao Xie <yuanhao.xie@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>

UefiCpuPkg/Library/MpInitLib/Ia32/MpFuncs.nasm

@@ -179,6 +179,14 @@ ProgramStack:
     mov         esp, dword [edi + CPU_INFO_IN_HOB.ApTopOfStack]
 
 CProcedureInvoke:
+    ;
+    ; Reserve 4 bytes for CpuMpData.
+    ; When the AP wakes up again via INIT-SIPI-SIPI, push 0 will cause the existing CpuMpData to be overwritten with 0.
+    ; CpuMpData is filled in via InitializeApData() during the first time INIT-SIPI-SIPI,
+    ; while overwirrten may occurs when under ApInHltLoop but InitFlag is not set to ApInitConfig.
+    ; Therefore reservation is implemented by sub esp instead of push 0.
+    ;
+    sub        esp, 4
     push       ebp               ; push BIST data at top of AP stack
     xor        ebp, ebp          ; clear ebp for call stack trace
     push       ebp