Merge pull request #5066 from kjbracey-arm/uartserial_readable

UARTSerial: Avoid readable() ambiguity

Author: theotherjimmy

drivers/UARTSerial.h

@@ -56,6 +56,12 @@ class UARTSerial : private SerialBase, public FileHandle, private NonCopyable<UA
      */
     virtual short poll(short events) const;
 
+    /* Resolve ambiguities versus our private SerialBase
+     * (for writable, spelling differs, but just in case)
+     */
+    using FileHandle::readable;
+    using FileHandle::writable;
+
     /** Write the contents of a buffer to a file
      *
      *  @param buffer   The buffer to write from