This patch narrows the subrange base type to INTEGER or CARDINAL
providing the range is satisfied.  It only does this when the subrange
base type is the ZTYPE.

gcc/m2/ChangeLog:

	* gm2-compiler/M2GCCDeclare.mod (DeclareSubrange): Check
	the base type of the subrange against the ZTYPE and call
	DeclareSubrangeNarrow if necessary.
	(DeclareSubrangeNarrow): New procedure function.

Signed-off-by: Gaius Mulley <gaiusmod2@gmail.com>