__STDC__ should be 1 (and not empty)

In http://qt-project.org/forums/viewthread/34477/ I describe the symptoms. Mysteriously, const disappears from some declarations and compilation of C++ code fails.

After searching for a long time, it turns out that the pre-defined preprocessor macro __STDC__ is defined but empty. According to K&R, it should be defined as "1".

The result is that when in the shiboken test cases some system headers are pulled in, it gets to preprocess a line like

#if __STDC__ || defined(__cplusplus)                                            

which after macro expansion looks like

#if  || defined(__cplusplus)     

which evaluates as false (due to syntax error). As a result, a pre-ANSI C compiler is assumed and "const" and a few more keywords are #defined away.

The fix is simple. See attached file.

Aside: I suspect that the code which suppresses macro expansion following the word "defined" is always active, and not just in preprocessor directives. That would be another bug, which I have not checked.

Aside 2: this affects at least the released version 1.2.1 but the bug tracker doesn't know about that version.