Typeprint: Resolve any dynamic target type of a pointer.

Before continuing with language specific type printing
we have to resolve the target type of a pointer
as we might wanna print more details of the target
like the dimension of an array. We have to resolve it here
as we don't have any address information later on.

2016-07-08  Bernhard Heckel  <bernhard.heckel@intel.com>

gdb/Changelog:
	* typeprint.c (whatis_exp): Resolve dynamic target type
	  of pointers.

gdb/Testsuite/Changelog:
	* gdb.cp/vla-cxx.cc: Added pointer to dynamic type.
	* gdb.cp/vla-cxx.exp: Test pointer to dynamic type.

Change-Id: Idff0d6dd0eab3125b45d470a12b5e66b392e42c3