cl/gcc-adapt-ext: added conditional compilation for <cp/cp-tree.h>

Related to issue #2 ->> This header file's position is dependent
on the version of the GCC used, at is seems.
cl/gcc-adapt-ext: lvalue references tests added
cl/gcc-adapt-ext: 1st proposed solution to C++ references problem
cl/gcc-adapt-ext: C++ native boolean type tested
cl/gcc-adapt-ext: simple script for testing C++ tests added

Useful to check the test is written correctly before running it in
GDB. Deciphering the error message there can be pain in the a**...
cl/gcc-adapt-ext: functions overloading & default arguments tests added
cl/gcc-adapt-ext: constant expressions tests prior to C++11 added
cl/gcc-adapt-ext: default initialization test for C++ added

Issue #4 @ https://github.com/deekej/predator/ discovered here.
cl/gcc-adapt-ext: zero and value initialization tests added
cl/gcc-adapt-ext: rest of the tests for initializations added

These tests are only dummy tests for now. They need update when the
support fot C++ STD library is added and they need a conditional
compilation to be C++98 compliant.
cl/gcc-adapt-ext: test for address of overloaded function added

TODO: This test has to be enabled after STDL support is added.
cl/gcc-adapt-ext: UNION_TYPE in 'get_decl_scope()' is handled now

Resolves #4 issue @ <https://github.com/deekej/predator/>.
cl/gcc-adapt-ext: 'run-test-cc1plus' now uses '-std=' correctly
cl/gcc-adapt-ext: vkdebug.sh.in fixed to use -D_GNU_SOURCE

Without this, including C STDL header files, like e.g.
<cstdlib>, results in many errors from undeclared types.
cl/gcc-adapt-ext: malloc(), calloc(), realloc() and free() test added

This tests the allocation done with the functions above, which are
defined as part of <cstdlib>. It also tests the 'placement new'
for calling the constructors of such created objects and explicit
calls of destructors.
cl/gcc-adapt-ext: Function member declaration context test included
cl/gcc-adapt-ext: basic tests for new/delete operators added

These tests don't include exception handling during allocation,
because exceptions handling is not yet implemented.

Also, 'placement new' is already tested in test n. 37...
cl/gcc-adapt-ext: test for POD class types added

Issue #8 @ <https://github.com/deekej/predator/> discovered here.
cl/gcc-adapt-ext: OFFSET_TYPE is now handled in 'read_specific_type()'

Fixes #8 issue @ <https://github.com/deekej/predator>.