cl/gcc-adapt-ext: C++ lvalue reference tests added to testsuite.
cl/gcc-adapt-ext: Test for lvalue reference vs. constant pointer added.
cl/gcc-adapt-ext: Handling of REFERENCE_TYPE implemented.

NOTE: The solution was chosen after previous e-mail conversation with
      both project lead developers of predator and forester.
Merge branch 'extension/lvalue-references' into cl/gcc-adapt-ext