Plugins: Add compilation database plugin

Introduce compilation database project support.

Pass the arguments list for each file directly to
ClangCodeModel via extraCodeModelFlags therefore
introduce a dependency from the ClangCodeModel plugin.

Change-Id: Iea5760d379de1ea246382dce56de0adf7ab5673d
Task-number: QTCREATORBUG-21115
Reviewed-by: Marco Bubke <marco.bubke@qt.io>

src/plugins/cpptools/compileroptionsbuilder.cpp

@@ -68,6 +68,14 @@ QStringList CompilerOptionsBuilder::build(CppTools::ProjectFile::Kind fileKind,
     addWordWidth();
     addTargetTriple();
     addExtraCodeModelFlags();
+
+    if (m_projectPart.toolchainType
+            == ProjectExplorer::Constants::COMPILATION_DATABASE_TOOLCHAIN_TYPEID) {
+        addHeaderPathOptions();
+        insertWrappedQtHeaders();
+        return options();
+    }
+
     updateLanguageOption(fileKind);
     addOptionsForLanguage(/*checkForBorlandExtensions*/ true);
     enableExceptions();