ArmPkg/DefaultExceptionHandlerLib: improve formatting of backtrace

ArmPkg/DefaultExceptionHandlerLib: improve formatting of backtrace

Implement the backtrace formattting suggested by Andrew, i.e.,

  IRQ Exception at 0x000000005BE182B0
  PC 0x00005BE182B0 (0x00005BE14000+0x000042B0) [ 0] ArmCpuDxe.dll
  PC 0x00005BE15770 (0x00005BE14000+0x00001770) [ 0] ArmCpuDxe.dll
  PC 0x00005EF08CC8 (0x00005EEEB000+0x0001DCC8) [ 1] DxeCore.dll
  PC 0x00005EF09008 (0x00005EEEB000+0x0001E008) [ 1] DxeCore.dll
  PC 0x00005EEF6ACC (0x00005EEEB000+0x0000BACC) [ 1] DxeCore.dll
  PC 0x00005EF0963C (0x00005EEEB000+0x0001E63C) [ 1] DxeCore.dll
  PC 0x00005EF09A38 (0x00005EEEB000+0x0001EA38) [ 1] DxeCore.dll
  PC 0x00005EF01560 (0x00005EEEB000+0x00016560) [ 1] DxeCore.dll
  PC 0x00005EF02FB4 (0x00005EEEB000+0x00017FB4) [ 1] DxeCore.dll
  PC 0x00005EF03098 (0x00005EEEB000+0x00018098) [ 1] DxeCore.dll
  PC 0x00005EF0460C (0x00005EEEB000+0x0001960C) [ 1] DxeCore.dll
  PC 0x00005EF005C4 (0x00005EEEB000+0x000155C4) [ 1] DxeCore.dll
  PC 0x00005EF00360 (0x00005EEEB000+0x00015360) [ 1] DxeCore.dll
  PC 0x00005EF003C8 (0x00005EEEB000+0x000153C8) [ 1] DxeCore.dll
  PC 0x00005EF128D0 (0x00005EEEB000+0x000278D0) [ 1] DxeCore.dll
  PC 0x00005EF12930 (0x00005EEEB000+0x00027930) [ 1] DxeCore.dll
  PC 0x00005EEEF594 (0x00005EEEB000+0x00004594) [ 1] DxeCore.dll
  PC 0x00005EF0CF18 (0x00005EEEB000+0x00021F18) [ 1] DxeCore.dll
  PC 0x00005EF1A310 (0x00005EEEB000+0x0002F310) [ 1] DxeCore.dll
  PC 0x00005EEF1808 (0x00005EEEB000+0x00006808) [ 1] DxeCore.dll
  PC 0x00005EEF1E48 (0x00005EEEB000+0x00006E48) [ 1] DxeCore.dll
  PC 0x00005EF0A838 (0x00005EEEB000+0x0001F838) [ 1] DxeCore.dll
  PC 0x00005EEED70C (0x00005EEEB000+0x0000270C) [ 1] DxeCore.dll
  PC 0x00005EEEC93C (0x00005EEEB000+0x0000193C) [ 1] DxeCore.dll
  PC 0x00005EEEC024 (0x00005EEEB000+0x00001024) [ 1] DxeCore.dll

  [ 0] /home/ard/build/edk2/Build/ArmVirtQemu-AARCH64/DEBUG_GCC5/AARCH64/ArmPkg/Drivers/CpuDxe/CpuDxe/DEBUG/ArmCpuDxe.dll
  [ 1] /home/ard/build/edk2/Build/ArmVirtQemu-AARCH64/DEBUG_GCC5/AARCH64/MdeModulePkg/Core/Dxe/DxeMain/DEBUG/DxeCore.dll

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>