Convert macros from plain QByteArray to a vector of structs

The old code model expected the macros as C++ formatted text
("#define Foo 42) but newer targets like the Clang codemodel expect key
value arguments like "-DFoo=42". So instead of parsing the text again and
again we use an abstract data description.

Task-number: QTCREATORBUG-17915
Change-Id: I0179fd13c48a581e91ee79bba9d42d501c26f19f
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

src/plugins/autotoolsprojectmanager/autotoolsproject.cpp

@@ -298,7 +298,7 @@ void AutotoolsProject::updateCppCodeModel()
             ? target->activeBuildConfiguration()->buildDirectory().toString() : QString();
 
     rpp.setIncludePaths(filterIncludes(absSrc, absBuild, m_makefileParserThread->includePaths()));
-    rpp.setDefines(m_makefileParserThread->defines());
+    rpp.setMacros(m_makefileParserThread->macros());
     rpp.setFiles(m_files);
 
     m_cppCodeModelUpdater->update({this, cToolChain, cxxToolChain, k, {rpp}});