Unhandled exception when booting UEFI x86_64 system image
Description of problem:
I have a bootable Ubuntu 20.04-based operating system image that I typically flash to the internal storage of an embedded Intel Atom computer. When I try booting it under QEMU, I reach the GRUB boot menu, but when it attempts to start the kernel, it outputs:

```
ERROR:../target/i386/tcg/sysemu/excp_helper.c:517:raise_stage2: code should not be reached
Bail out! ERROR:../target/i386/tcg/sysemu/excp_helper.c:517:raise_stage2: code should not be reached
Aborted (core dumped)
``` 

The kernel settings configured in GRUB are:

```
linux         /boot/vmlinuz-5.4.0-132-generic root=UUID=816fe083-fc26-4a0d-ae4a-68d1b16dfb66 ro console=uart,mmio32,0xd091c000 console=ttyS4,115200n8 console=tty0                                                         ?
initrd        /boot/initrd.img-5.4.0-132-generic 
```

If I run an older QEMU 4.2.1 that ships with Ubuntu:

```
!!!! X64 Exception Type - 0D(#GP - General Protection)  CPU Apic ID - 00000000 !!!!
ExceptionData - 0000000000000000
RIP  - 0000000007F2CD0E, CS  - 0000000000000038, RFLAGS - 0000000000200206
RAX  - AFAFAFAFAFAFAFAF, RCX - 000000000657F408, RDX - AFAFAFAFAFAFAFAF
RBX  - 0000000000000288, RSP - 0000000007F1BC48, RBP - 0000000007F336A0
RSI  - 0000000007F336F8, RDI - 0000000000001000
R8   - 000000000657F408, R9  - 0000000000000320, R10 - 0000000000000000
R11  - 0000000000000000, R12 - 0000000000000004, R13 - 000000000657F400
R14  - 0000000000000000, R15 - 0000000000000000
DS   - 0000000000000030, ES  - 0000000000000030, FS  - 0000000000000030
GS   - 0000000000000030, SS  - 0000000000000030
CR0  - 0000000080010033, CR2 - 0000000000000000, CR3 - 0000000007C01000
CR4  - 0000000000000668, CR8 - 0000000000000000
DR0  - 0000000000000000, DR1 - 0000000000000000, DR2 - 0000000000000000
DR3  - 0000000000000000, DR6 - 00000000FFFF0FF0, DR7 - 0000000000000400
GDTR - 0000000007BEEA98 0000000000000047, LDTR - 0000000000000000
IDTR - 00000000072D1018 0000000000000FFF,   TR - 0000000000000000
FXSAVE_STATE - 0000000007F1B8A0
!!!! Find image based on IP(0x7F2CD0E) /build/edk2-xUnmxG/edk2-0~20191122.bd85bf54/Build/OvmfX64/RELEASE_GCC5/X64/MdeModulePkg/Core/Dxe/DxeMain/DEBUG/DxeCore.dll (ImageBase=0000000007F1D000, EntryPoint=0000000007F2FAAE) !!!!
```