fortran: array descriptor: Rename dim subfields internal accessors [PR122521]

Drop the gfc prefix from the internal function giving access to the lbound,
ubound, and stride fields.  This aligns the function names with the rest of
the compiler dropping the prefix for static functions.

	PR fortran/122521

gcc/fortran/ChangeLog:

	* trans-descriptor.cc (gfc_conv_descriptor_stride): Rename ...
	(conv_descriptor_stride): ... to this.
	(gfc_conv_descriptor_stride_get, gfc_conv_descriptor_stride_set):
	Update caller.
	(gfc_conv_descriptor_lbound): Rename ...
	(conv_descriptor_lbound): ... to this.
	(gfc_conv_descriptor_lbound_get, gfc_conv_descriptor_lbound_set):
	Update caller.
	(gfc_conv_descriptor_ubound): Rename ...
	(conv_descriptor_ubound): ... to this.
	(gfc_conv_descriptor_ubound_get, gfc_conv_descriptor_ubound_set):
	Update caller.