gdb: Print cv qualifiers if class attributes are substituted

Make ptype print const/volatile qualifiers when template or typedef
attributes are substituted.

For a programm like
~~~
template<typename DataT>
class Cfoo
{
  typedef float myfloat;
public:
  DataT me0;
  const DataT me1=1;
  const myfloat me2=2.0;
};

int main()
{
  Cfoo<int> cfoo;
  return 0;
}
~~~

gdb outputs the following type for cfoo's attributes:

~~~
(gdb) b 14
Breakpoint 1 at 0x1170: file tmp.cc, line 14.
(gdb) run
Starting program: /tmp

Breakpoint 1, main () at tmp.cc:14
14        return 0;
(gdb) ptype cfoo
type = class Cfoo<int> [with DataT = int] {
  public:
    DataT me0;
    DataT me1;
    myfloat me2;

  private:
    typedef float myfloat;
}

~~~

The cv qualifiers (const in this case) are ignored for me1 and me2.

After:
~~~
(gdb) ptype cfoo
type = class Cfoo<int> [with DataT = int] {
  public:
    DataT me0;
    const DataT me1;
    const myfloat me2;

  private:
    typedef float myfloat;
}
~~~

gdb/ChangeLog:
2021-11-16  Christina Schimpe  <christina.schimpe@intel.com>

	* gdb/c-typeprint.c: Print cv qualifiers in case of parameter
	  substitution.

gdb/testsuite/ChangeLog:
2021-11-16  Christina Schimpe  <christina.schimpe@intel.com>

	* gdb.cp/templates.cc: 	New template class Cfoo with const,
	  template, typdef and integer attributes.
	* gdb.cp/templates.exp: Add new test using ptype and ptype/r
	  commmands for template class CFoo.