analyzer: fix another ICE in constructor-handling [PR96949]

analyzer: fix another ICE in constructor-handling [PR96949]

PR analyzer/96949 reports an ICE with
--param analyzer-max-svalue-depth=0, where the param value leads
to INTEGER_CST values in a RANGE_EXPR being treated as unknown
symbolic values.

This patch replaces implicit assumptions that these values are
concrete (and thus have concrete bit offsets), adding
error-handling for symbolic cases instead of assertions.

gcc/analyzer/ChangeLog:
	PR analyzer/96949
	* store.cc (binding_map::apply_ctor_val_to_range): Add
	error-handling for the cases where we have symbolic offsets.

gcc/testsuite/ChangeLog:
	PR analyzer/96949
	* gfortran.dg/analyzer/pr96949.f90: New test.