Fix evaluation of method calls under EVAL_SKIP.

Fix evaluation of method calls under EVAL_SKIP.

When evaluating method calls under EVAL_SKIP, the "object" and the
arguments to the method should also be evaluated under EVAL_SKIP,
instead of skipping to evaluate them as was being done previously.

gdb/ChangeLog:

	PR c++/17494
	* eval.c (evaluate_subexp_standard): Evaluate the "object" and
	the method args also under EVAL_SKIP when evaluating method
	calls under EVAL_SKIP.

gdb/testsuite/ChangeLog:

	PR c++/17494
	* gdb.cp/pr17494.cc: New file.
	* gdb.cp/pr17494.exp: New file.