The circuit court of any county, within which is situated any city which has undergone transition from a city of the second class to a city of the first class since the Constitution of 1902, went into effect, shall have concurrent jurisdiction with the circuit court of such city in all proceedings at law or in equity, except criminal prosecutions; and the circuit court of such county shall constitute the circuit court of such city. This section shall not apply to the Cities of Bristol, Colonial Heights, Fredericksburg, Martinsville, Salem and Suffolk for which separate circuit courts have heretofore been established and which are continued.