[Incremental] Plumb -verify-incremental-dependencies Through The Frontend and Driver

When enabled at the driver level, the frontends will inherit the flag. For each frontend that recieves this option, all primaries will have their reference dependencies validated.

lib/Frontend/ArgsToFrontendOptionsConverter.cpp

@@ -176,6 +176,7 @@ bool ArgsToFrontendOptionsConverter::convert(
 
   Opts.EnableSourceImport |= Args.hasArg(OPT_enable_source_import);
   Opts.ImportUnderlyingModule |= Args.hasArg(OPT_import_underlying_module);
+  Opts.VerifyDependencies |= Args.hasArg(OPT_verify_incremental_dependencies);
 
   computeImportObjCHeaderOptions();
   computeImplicitImportModuleNames();