Clean-up the code that stored and passes the SILSerializeAll flag around.

- SILSerializeAll flag is now stored in the SILOptions and passed around as part of it
- Explicit SILSerializeAll/wholeModuleSerialized/makeModuleFragile API parameters are removed in many places

lib/FrontendTool/FrontendTool.cpp

@@ -691,13 +691,13 @@ static bool performCompile(CompilerInstance &Instance,
       }
       astGuaranteedToCorrespondToSIL = !fileIsSIB(PrimaryFile);
       SM = performSILGeneration(*PrimaryFile, Invocation.getSILOptions(),
-                                None, opts.SILSerializeAll);
+                                None);
     } else {
       auto mod = Instance.getMainModule();
       astGuaranteedToCorrespondToSIL =
           llvm::none_of(mod->getFiles(), fileIsSIB);
       SM = performSILGeneration(mod, Invocation.getSILOptions(),
-                                opts.SILSerializeAll, true);
+                                true);
     }
   }
 
@@ -835,7 +835,8 @@ static bool performCompile(CompilerInstance &Instance,
       serializationOpts.OutputPath = opts.ModuleOutputPath.c_str();
       serializationOpts.DocOutputPath = opts.ModuleDocOutputPath.c_str();
       serializationOpts.GroupInfoPath = opts.GroupInfoPath.c_str();
-      serializationOpts.SerializeAllSIL = opts.SILSerializeAll;
+      serializationOpts.SerializeAllSIL =
+          Invocation.getSILOptions().SILSerializeAll;
       if (opts.SerializeBridgingHeader)
         serializationOpts.ImportedHeader = opts.ImplicitObjCHeaderPath;
       serializationOpts.ModuleLinkName = opts.ModuleLinkName;