Fixes moc parsing of (#__VA_ARGS__) expressions

glibc 2.25 introduced code like the following in
/usr/include/sys/sysmacros.h:

#define __SYSMACROS_DM(symbol) __SYSMACROS_DM1 \
 (In the GNU C Library, symbol is defined\n\
  by <sys/sysmacros.h>. For historical compatibility, it is\n\
  currently defined by <sys/types.h> as well, but we plan to\n\
  remove this soon.  To use #symbol, include <sys/sysmacros.h>\n\
  directly.  If you did not intend to use a system-defined macro\n\
  #symbol, you should undefine it after including <sys/types.h>.)

(where __SYSMACROS_DM1 is defined as:
#define __SYSMACROS_DM1(...) __glibc_macro_warning (#__VA_ARGS__)
)

when parsing that with moc, it gives the following parse error:
/usr/include/glib-2.0/gobject/gtype.h:52: Parse error at "defined"

This patch fixes this, so it ignores arguments passed to
(#__VA_ARGS__) since they're supposed to be strings anyway.

Index: qt-everywhere-opensource-src-4.8.7/src/tools/moc/preprocessor.cpp
===================================================================
--- qt-everywhere-opensource-src-4.8.7.orig/src/tools/moc/preprocessor.cpp
+++ qt-everywhere-opensource-src-4.8.7/src/tools/moc/preprocessor.cpp
@@ -535,6 +535,21 @@ void Preprocessor::substituteUntilNewlin
             MacroName macro = symbol();
             if (macros.contains(macro) && !safeset.contains(macro)) {
                 substituteMacro(macro, substituted, safeset);
+                if (substituted.count()>4)
+                {
+                    int i=substituted.count()-4;
+                    if (substituted.at(i).lexem()=="("
+                       && substituted.at(i+1).lexem()=="#"
+                       && substituted.at(i+2).lexem()=="__VA_ARGS__"
+                       && substituted.at(i+3).lexem()==")")
+                    {
+                       // Let's ignore the following expression, since it'll considered a string, and so, it's better not to parse it.
+                       if (test(PP_LPAREN)) {
+                           while (!test(PP_RPAREN)) next();
+                       }
+
+                    }
+                }
                 continue;
             }
         } else if (token == PP_DEFINED) {