[lldb] Fix UBSan complaints for #151460

Author: igorkudrin

lldb/source/Plugins/Process/Utility/RegisterInfoPOSIX_arm64.h

@@ -46,9 +46,9 @@ class RegisterInfoPOSIX_arm64
 
   // based on RegisterContextDarwin_arm64.h
   // Pack this so there are no extra bytes, but align its start address to at
-  // least 4 bytes to prevent alignment errors on Arm 32-bit.
+  // least 8 bytes to prevent alignment errors.
   LLVM_PACKED_START
-  struct alignas(4) GPR {
+  struct alignas(8) GPR {
     uint64_t x[29]; // x0-x28
     uint64_t fp;    // x29
     uint64_t lr;    // x30

lldb/unittests/Instruction/ARM64/TestAArch64Emulator.cpp

@@ -62,7 +62,7 @@ struct Arch64EmulatorTester : public EmulateInstructionARM64 {
       reg_value.SetUInt64(tester->gpr.pc);
       return true;
     case gpr_cpsr_arm64:
-      reg_value.SetUInt64(tester->gpr.cpsr);
+      reg_value.SetUInt32(tester->gpr.cpsr);
       return true;
     default:
       return false;
@@ -97,7 +97,7 @@ struct Arch64EmulatorTester : public EmulateInstructionARM64 {
       tester->gpr.pc = reg_value.GetAsUInt64();
       return true;
     case gpr_cpsr_arm64:
-      tester->gpr.cpsr = reg_value.GetAsUInt64();
+      tester->gpr.cpsr = reg_value.GetAsUInt32();
       return true;
     default:
       return false;
@@ -112,7 +112,7 @@ struct Arch64EmulatorTester : public EmulateInstructionARM64 {
     assert(addr - tester->memory_offset + length <= sizeof(tester->memory));
     if (addr >= tester->memory_offset &&
         addr - tester->memory_offset + length <= sizeof(tester->memory)) {
-      memcpy(dst, tester->memory + addr - tester->memory_offset, length);
+      memcpy(dst, tester->memory + (addr - tester->memory_offset), length);
       return length;
     }
     return 0;