[Build/CPU] Remove #pragma pack from Export and PPCOpcodeDisasmInfo

Pack(1) causes unaligned pointer errors on ARM64 with Apple's linker.
These are static read-only tables where the ~9KB size savings from
packing is negligible. Removing the pack may also marginally improve
access speed on x86 by avoiding unaligned loads.

src/xenia/cpu/export_resolver.h

@@ -69,7 +69,6 @@ struct ExportTag {
 typedef void (*xe_kernel_export_shim_fn)(void*, void*);
 
 typedef void (*ExportTrampoline)(ppc::PPCContext* ppc_context);
-#pragma pack(push, 1)
 class Export {
  public:
   enum class Type {
@@ -113,7 +112,6 @@ class Export {
                                                  : Type::kFunction;
   }
 };
-#pragma pack(pop)
 class ExportResolver {
  public:
   class Table {

src/xenia/cpu/ppc/ppc_opcode_info.h

@@ -133,7 +133,6 @@ enum class PPCOpcodeField : uint32_t {
   kTO,
   kLEV,
 };
-#pragma pack(push, 1)
 struct PPCOpcodeDisasmInfo {
   PPCOpcodeGroup group;
   PPCOpcodeFormat format;
@@ -144,7 +143,6 @@ struct PPCOpcodeDisasmInfo {
   // std::vector<PPCOpcodeField> writes;
   InstrDisasmFn disasm;
 };
-#pragma pack(pop)
 PPCOpcode LookupOpcode(uint32_t code);
 
 const PPCOpcodeInfo& GetOpcodeInfo(PPCOpcode opcode);