CppTools: Ignore generated symbols in SearchSymbols

...e.g. qt_metacall() etc from the Q_OBJECT macro.

This affects the results of the cpp locator and find filters.

Change-Id: I2f9ff1210f3705baddadd486d700ee8be9a44a20
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>

tests/cpplocators/testdata_basic/file1.cpp

@@ -1,9 +1,13 @@
 // Copyright header
 
+#define GENERATE_FUNC void myFunctionGenerated() {}
+
 //
 // Symbols in a global namespace
 //
 
+GENERATE_FUNC
+
 int myVariable;
 
 int myFunction(bool yesno, int number) {}