fortran: ICE using undeclared symbol in array constructor PR93484

fortran: ICE using undeclared symbol in array constructor PR93484

Using undeclared symbol k in an expression in the following
array constructor results in an ICE:

    print *, [real(x(k))]

If the call to the intrinsic is not in a constructor a no IMPLICIT
type error is reported and the ICE does not occur.

Matching on an expression instead of an initialisation express an
and not converting a MATCH_ERROR return value into MATCH_NO results
in the no IMPLICIT error and no ICE.

Note: Steven G. Kargl  <kargl@gcc.gnu.org> is the author of the
changes except for the test cases.

gcc/fortran/ChangeLog:

	Backport from master
	2020-03-25  Mark Eggleston <markeggleston@gcc.gnu.org>

	PR fortran/93484
	* match.c (gfc_match_type_spec): Replace gfc_match_init_expr with
	gfc_match_expr. Return m if m is MATCH_NO or MATCH_ERROR.

gcc/testsuite

	Backport from master
	2020-03-25  Mark Eggleston <markeggleston@gcc.gnu.org>

	PR fortran/93484
	* gfortran.dg/pr93484_1.f90: New test.
	* gfortran.dg/pr93484_2.f90: New test.