Fix missing-field-initializer warnings

src/gb/gbMemory.cpp

@@ -1013,7 +1013,8 @@ mapperHuC3RTC gbRTCHuC3 = {
     0, // DateTime
     0, // WritingTime
     0, // ModeFlag
-    0 // ClockShift
+    0, // ClockShift
+    { 0 }
 };
 
 void memoryUpdateHuC3Latch() {

src/libretro/libretro.cpp

@@ -970,7 +970,7 @@ static bool option_swapAnalogSticks;
 
 static void update_variables(bool startup)
 {
-    struct retro_variable var = {0};
+    struct retro_variable var = { NULL, NULL };
     char key[256] = {0};
     int disabled_layers = 0;
     int sound_enabled = 0x30F;

src/libretro/libretro_core_options.h

@@ -618,7 +618,7 @@ struct retro_core_option_v2_definition option_defs_us[] = {
         },
         "enabled"
     },
-    { NULL, NULL, NULL, NULL, NULL, NULL, {{0}}, NULL },
+    { NULL, NULL, NULL, NULL, NULL, NULL, { { NULL, NULL } }, NULL },
 };
 
 struct retro_core_options_v2 options_us = {

src/libretro/libretro_core_options_intl.h

@@ -613,7 +613,8 @@ struct retro_core_option_v2_definition option_defs_tr[] = {
         },
         "enabled"
     },
-    { NULL, NULL, NULL, NULL, NULL, NULL, {{0}}, NULL },
+
+    { NULL, NULL, NULL, NULL, NULL, NULL, { { NULL, NULL } }, NULL },
 };
 
 struct retro_core_options_v2 options_tr = {