Clang: Add Symbol Indexing

It is a first step and now a database is generated if you start QtCreator.
Some code is now shared with the PchManager which can be improved in the
future.

Change-Id: Ic267fe7960f6c455d91832859a673ce98f269aa2
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

tests/unit/unittest/sqlitedatabase-test.cpp

@@ -96,6 +96,18 @@ TEST_F(SqliteDatabase, AddTable)
     ASSERT_THAT(database.tables(), Contains(sqliteTable));
 }
 
+TEST_F(SqliteDatabase, TableIsReadyAfterOpenDatabase)
+{
+    database.close();
+    auto &table = database.addTable();
+    table.setName("foo");
+    table.addColumn("name");
+
+    database.open();
+
+    ASSERT_TRUE(table.isReady());
+}
+
 void SqliteDatabase::SetUp()
 {
     database.setJournalMode(JournalMode::Memory);