Allow the Eclipse CDT parser to resolve #include directives.
This still does not work for includes of system headers
like <stdio.h>, <assert.h> etc.,
but it does work for includes of headers from the same directory.
This means in cases where there are only local headers
(no system headers),
there is no need for an external pre-processor anymore
(so you can omit -preprocess).

It does not work yet for system headers
because therefore we would need to specify
the correct include directories,
and these vary from system to system
(depending on architecture and GCC version).

git-svn-id: https://svn.sosy-lab.org/software/cpachecker/trunk@13261 4712c6d2-40bb-43ae-aa4b-fec3f1bdfe4c