Fortran: Fix ex-module inherited PDT parameter namespaces [PR104750]

2026-09-03 Amir Shahmoradi  <shahmoradi@lanl.gov>
	   Paul Thomas  <pault@gcc.gnu.org>

gcc/fortran
	PR fortran/104750
	* module.cc (mio_full_f2k_derived) : Instead of transferring
	the sym_root from the formal namespace, call mio_f2k_derived so
	that all required symbols and references are fully loaded.
	(read_cleanup): Restore named symtree entries for referenced
	PDT type specification parameters during module cleanup, while
	preserving existing handling for ordinary hidden symbols and
	ignoring formal parameters without namespaces.
	(fixup_pdt_parameter_namespaces): A new function that transfers
	the namespace of locally declared PDT type specification parms
	to the derived-type namespace after skipping inherited parameters,
	preserving the existing namespace ownership and ref counting.
	(read_module): Call the new fcn after read_cleanup, so that the
	required symbol and formal-parameter information has been fully
	reconstructed first.

gcc/testsuite
	PR fortran/104750
	* gfortran.dg/pdt_93.f90: New test.