Fixed non-debug build warning

src/core/lib/gpr/alloc.cc

@@ -34,12 +34,14 @@ static void* zalloc_with_gpr_malloc(size_t sz) {
   return p;
 }
 
+#ifndef NDEBUG
 static constexpr bool is_power_of_two(size_t value) {
   // 2^N =     100000...000
   // 2^N - 1 = 011111...111
   // (2^N) && ((2^N)-1)) = 0
   return (value & (value - 1)) == 0;
 }
+#endif
 
 static void* aligned_alloc_with_gpr_malloc(size_t size, size_t alignment) {
   GPR_DEBUG_ASSERT(is_power_of_two(alignment));

src/core/lib/gprpp/arena.cc

@@ -35,8 +35,8 @@ namespace {
 
 void* ArenaStorage(size_t initial_size) {
   static constexpr size_t base_size =
-      GPR_ROUND_UP_TO_ALIGNMENT_SIZE(sizeof(grpc_core::Arena));
+      GPR_ROUND_UP_TO_MAX_ALIGNMENT_SIZE(sizeof(grpc_core::Arena));
-  initial_size = GPR_ROUND_UP_TO_ALIGNMENT_SIZE(initial_size);
+  initial_size = GPR_ROUND_UP_TO_MAX_ALIGNMENT_SIZE(initial_size);
   size_t alloc_size = base_size + initial_size;
   static constexpr size_t alignment =
       (GPR_CACHELINE_SIZE > GPR_MAX_ALIGNMENT &&