Add assert() statements to demonstrate that memory allocations are always

aligned to an 8-byte boundary (unless SQLITE_4_BYTE_ALIGNED_MALLOC is defined).

FossilOrigin-Name: 305cc4e6c1164b1ede0c3177e3c0f9b8644df0f6

src/malloc.c

@@ -307,6 +307,7 @@ void *sqlite3Malloc(int n){
   }else{
     p = sqlite3GlobalConfig.m.xMalloc(n);
   }
+  assert( EIGHT_BYTE_ALIGNMENT(p) );  /* IMP: R-36023-12588 */
   return p;
 }
 
@@ -544,6 +545,7 @@ void *sqlite3Realloc(void *pOld, int nBytes){
   }else{
     pNew = sqlite3GlobalConfig.m.xRealloc(pOld, nNew);
   }
+  assert( EIGHT_BYTE_ALIGNMENT(pNew) ); /* IMP: R-36023-12588 */
   return pNew;
 }