[CodeCompletion] Remove two completion options from LangOptions

"add inits to toplevel" and "call pattern heuristics" are only used in
code completion. Move them from LangOptions to CodeCompletionContext so
that they don't affect compiler arguments.

lib/Frontend/CompilerInvocation.cpp

@@ -501,12 +501,6 @@ static bool ParseLangArgs(LangOptions &Opts, ArgList &Args,
     }
   }
 
-  Opts.CodeCompleteInitsInPostfixExpr |=
-      Args.hasArg(OPT_code_complete_inits_in_postfix_expr);
-
-  Opts.CodeCompleteCallPatternHeuristics |=
-      Args.hasArg(OPT_code_complete_call_pattern_heuristics);
-
   if (auto A = Args.getLastArg(OPT_enable_target_os_checking,
                                OPT_disable_target_os_checking)) {
     Opts.EnableTargetOSChecking