Specify maximum array size for QByteArray.

Task-number: QTBUG-33037
Change-Id: I3f39b1498fc70614402fca2281ffbd1a6ec4cf3f
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/tools/qbytearray.cpp

@@ -645,6 +645,8 @@ static inline char qToLower(char c)
     store raw binary data, and when memory conservation is critical
     (e.g., with Qt for Embedded Linux).
 
+    The maximum array size of a QByteArray is under 2^30.
+
     One way to initialize a QByteArray is simply to pass a \c{const
     char *} to its constructor. For example, the following code
     creates a byte array of size 5 containing the data "Hello":