Treat OP_F77_UNDETERMINED_ARGLIST as OP_FUNCALL

Treat OP_F77_UNDETERMINED_ARGLIST as OP_FUNCALL

When I debug some fortran expression parsing, I got

(gdb) set debug expression 1
(gdb) p intvla(5,5,5)
Dump of expression @ 0x205fa80, before conversion to prefix form:
	Language fortran, 19 elements, 16 bytes each.
	Index                Opcode         Hex Value  String Value
	    0          OP_VAR_VALUE  40  (...............
	    1    <unknown 31863232>  31863232  .1..............
....
	   14             BINOP_REM  5  ................
	   15               OP_LONG  38  &...............
	   16  OP_F77_UNDETERMINED_ARGLIST  48  0...............
	   17             BINOP_MUL  3  ................
	   18  OP_F77_UNDETERMINED_ARGLIST  48  0...............
Dump of expression @ 0x205fa80, after conversion to prefix form:
Expression: `Invalid expression
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

This patch fixes this problem by handling OP_F77_UNDETERMINED_ARGLIST in
the same way as handling OP_FUNCALL.  With this patch applied, the output
looks better,

(gdb) p intvla (5,5,5)
Dump of expression @ 0x2d75590, before conversion to prefix form:
	Language fortran, 19 elements, 16 bytes each.
	Index                Opcode         Hex Value  String Value
	    0          OP_VAR_VALUE  40  (...............
....
	   16  OP_F77_UNDETERMINED_ARGLIST  48  0...............
	   17             BINOP_MUL  3  ................
	   18  OP_F77_UNDETERMINED_ARGLIST  48  0...............
Dump of expression @ 0x2d75590, after conversion to prefix form:
Expression: `vla_primitives::intvla (5, 5, 5)'
	Language fortran, 19 elements, 16 bytes each.

	    0  OP_F77_UNDETERMINED_ARGLIST  Number of args: 3
	    3    OP_VAR_VALUE          Block @0x297e1c0, symbol @0x297cd50 (intvla)
	    7    OP_LONG               Type @0x2976900 (int), value 5 (0x5)
	   11    OP_LONG               Type @0x2976900 (int), value 5 (0x5)
	   15    OP_LONG               Type @0x2976900 (int), value 5 (0x5)

gdb:

2018-02-06  Yao Qi  <yao.qi@linaro.org>

	* expprint.c (print_subexp_standard): Handle
	OP_F77_UNDETERMINED_ARGLIST.
	(dump_subexp_body_standard): Likewise.