fortran: allow character in conditional expression

fortran: allow character in conditional expression

This patch allows the use of character types in conditional expressions.

gcc/fortran/ChangeLog:

	* resolve.cc (resolve_conditional): Allow character in cond-expr.
	* trans-const.cc (gfc_conv_constant): Handle want_pointer.
	* trans-expr.cc (gfc_conv_conditional_expr): Fill se->string_length.
	(gfc_conv_string_parameter): Handle COND_EXPR tree code.

gcc/testsuite/ChangeLog:

	* gfortran.dg/conditional_1.f90: Test character type.
	* gfortran.dg/conditional_2.f90: Test print constants.
	* gfortran.dg/conditional_4.f90: Test diagnostic message.
	* gfortran.dg/conditional_6.f90: Test character cond-arg.