compat/atomics: fix atomic_fetch_xor

compat/atomics/dummy/stdatomic.h

@@ -156,7 +156,7 @@ FETCH_MODIFY(and, &)
     atomic_fetch_or(object, operand)
 
 #define atomic_fetch_xor_explicit(object, operand, order) \
-    atomic_fetch_sub(object, operand)
+    atomic_fetch_xor(object, operand)
 
 #define atomic_fetch_and_explicit(object, operand, order) \
     atomic_fetch_and(object, operand)

compat/atomics/gcc/stdatomic.h

@@ -147,10 +147,10 @@ do {                                    \
     atomic_fetch_or(object, operand)
 
 #define atomic_fetch_xor(object, operand) \
-    __sync_fetch_and_sub(object, operand)
+    __sync_fetch_and_xor(object, operand)
 
 #define atomic_fetch_xor_explicit(object, operand, order) \
-    atomic_fetch_sub(object, operand)
+    atomic_fetch_xor(object, operand)
 
 #define atomic_fetch_and(object, operand) \
     __sync_fetch_and_and(object, operand)

compat/atomics/pthread/stdatomic.h

@@ -177,7 +177,7 @@ FETCH_MODIFY(and, &)
     atomic_fetch_or(object, operand)
 
 #define atomic_fetch_xor_explicit(object, operand, order) \
-    atomic_fetch_sub(object, operand)
+    atomic_fetch_xor(object, operand)
 
 #define atomic_fetch_and_explicit(object, operand, order) \
     atomic_fetch_and(object, operand)

compat/atomics/suncc/stdatomic.h

@@ -166,7 +166,7 @@ static inline intptr_t atomic_fetch_and(intptr_t *object, intptr_t operand)
     atomic_fetch_or(object, operand)
 
 #define atomic_fetch_xor_explicit(object, operand, order) \
-    atomic_fetch_sub(object, operand)
+    atomic_fetch_xor(object, operand)
 
 #define atomic_fetch_and_explicit(object, operand, order) \
     atomic_fetch_and(object, operand)

compat/atomics/win32/stdatomic.h

@@ -159,7 +159,7 @@ static inline int atomic_compare_exchange_strong(intptr_t *object, intptr_t *exp
     atomic_fetch_or(object, operand)
 
 #define atomic_fetch_xor_explicit(object, operand, order) \
-    atomic_fetch_sub(object, operand)
+    atomic_fetch_xor(object, operand)
 
 #define atomic_fetch_and_explicit(object, operand, order) \
     atomic_fetch_and(object, operand)