make C90 compatible

Author: tom-pytel

Include/cpython/pyatomic.h

@@ -552,14 +552,16 @@ _Py_atomic_load_ssize_acquire(const Py_ssize_t *obj);
 static inline void *
 _Py_atomic_memcpy_ptr_store_relaxed(void *dest, void *src, size_t n)
 {
+    void **dest_, **src_, **end;
+
     assert(((uintptr_t)dest & (uintptr_t)(sizeof (void *) - 1)) == 0);
     assert(((uintptr_t)src & (uintptr_t)(sizeof (void *) - 1)) == 0);
     assert(n % (size_t)sizeof(void *) == 0);
 
     if (dest != src) {
-        void **dest_ = (void **)dest;
-        void **src_ = (void **)src;
-        void **end = dest_ + n / sizeof(void *);
+        dest_ = (void **)dest;
+        src_ = (void **)src;
+        end = dest_ + n / sizeof(void *);
 
         for (; dest_ != end; dest_++, src_++) {
             _Py_atomic_store_ptr_relaxed(dest_, *src_);
@@ -572,24 +574,26 @@ _Py_atomic_memcpy_ptr_store_relaxed(void *dest, void *src, size_t n)
 static inline void *
 _Py_atomic_memmove_ptr_store_relaxed(void *dest, void *src, size_t n)
 {
+    void **dest_, **src_, **end;
+
     assert(((uintptr_t)dest & (uintptr_t)(sizeof (void *) - 1)) == 0);
     assert(((uintptr_t)src & (uintptr_t)(sizeof (void *) - 1)) == 0);
     assert(n % (size_t)sizeof(void *) == 0);
 
     if (dest < src || dest >= (void *)((char *)src + n)) {
-        void **dest_ = (void **)dest;
-        void **src_ = (void **)src;
-        void **end = dest_ + n / sizeof(void *);
+        dest_ = (void **)dest;
+        src_ = (void **)src;
+        end = dest_ + n / sizeof(void *);
 
         for (; dest_ != end; dest_++, src_++) {
             _Py_atomic_store_ptr_relaxed(dest_, *src_);
         }
     }
     else if (dest > src) {
         n = n / sizeof(void *) - 1;
-        void **dest_ = (void **)dest + n;
-        void **src_ = (void **)src + n;
-        void **end = (void **)dest - 1;
+        dest_ = (void **)dest + n;
+        src_ = (void **)src + n;
+        end = (void **)dest - 1;
 
         for (; dest_ != end; dest_--, src_--) {
             _Py_atomic_store_ptr_relaxed(dest_, *src_);