This patch adds native support for SQL_REAL (float) and SQL_SMALLINT
(short). Previously those datatypes were mapped to double and integer.
[ChangeLog][QtSql] The ODBC driver now properly maps QMetaType::Float to
real sql datatype and QMetaType::Short to smallint
Fixes: QTBUG-8963
Fixes: QTBUG-57279
Change-Id: Ifec4c609734dbe6165c1ebdadb461c2aae47ba78
Reviewed-by: Andy Shaw <andy.shaw@qt.io>