Avoid shift UB for large arrays

Don't shift into the sign bit.

Author: nikic

Zend/zend_hash.c

@@ -102,14 +102,14 @@ static zend_always_inline uint32_t zend_hash_check_size(uint32_t nSize)
 
 #if defined(ZEND_WIN32)
 	if (BitScanReverse(&index, nSize - 1)) {
-		return 0x2 << ((31 - index) ^ 0x1f);
+		return 0x2u << ((31 - index) ^ 0x1f);
 	} else {
 		/* nSize is ensured to be in the valid range, fall back to it
 		   rather than using an undefined bis scan result. */
 		return nSize;
 	}
 #elif (defined(__GNUC__) || __has_builtin(__builtin_clz))  && defined(PHP_HAVE_BUILTIN_CLZ)
-	return 0x2 << (__builtin_clz(nSize - 1) ^ 0x1f);
+	return 0x2u << (__builtin_clz(nSize - 1) ^ 0x1f);
 #else
 	nSize -= 1;
 	nSize |= (nSize >> 1);