message: Fix warning: suggest braces around initialization of subobject
  This patch adds braces to the DEFINE_XMM macro.
diff: @@ -75,11 +75,13 @@ typedef struct _FPReg {
  (sizeof(GPR) + LLVM_EXTENSION offsetof(FPReg, regname))
  #define DEFINE_XMM(reg) \
  -#reg, NULL, sizeof(((FPReg *)nullptr)->reg), FPR_OFFSET(reg), eEncodingUint, \
  - eFormatVectorOfUInt64, \
  + { \
  +#reg, NULL, sizeof(((FPReg *)nullptr)->reg), FPR_OFFSET(reg), \
  + eEncodingUint, eFormatVectorOfUInt64, \
  {dwarf_##reg##_x86_64, dwarf_##reg##_x86_64, LLDB_INVALID_REGNUM, \
  LLDB_INVALID_REGNUM, lldb_##reg##_x86_64 }, \
  - nullptr, nullptr, nullptr, 0
  + nullptr, nullptr, nullptr, 0 \
  + }
  // clang-format off
  static RegisterInfo g_register_infos_x86_64[] = {
  