This patch removes the GetSymbolVendor function, and the various
mentions of the SymbolVendor in the Module class. The implementation of
GetSymbolVendor is "inlined" into the GetSymbolFile class which I
After this patch, the SymbolVendor class still exists inside the Module
object, but only as an implementation detail -- a fancy holder for the
SymbolFile. That will be removed in the next patch.