[lld/COFF] Use P_priv more

[thakis]

Summary

P_priv does the same as the old QF further down. Standardize on P_priv.

[mstorsjo]

LGTM

lld/COFF/Options.td

 def print_symbol_order: P<
     "print-symbol-order",
     "Print a symbol order specified by /call-graph-ordering-file and "
     "/call-graph-profile-sort into the specified file">;
 def wrap : P_priv<"wrap">;
 
 // Flags for debugging
 def lldmap : F<"lldmap">;
-def lldmap_file : Joined<["/", "-", "/?", "-?"], "lldmap:">;
+def lldmap_file : P_priv<"lldmap">;
 def map : F<"map">;
-def map_file : Joined<["/", "-", "/?", "-?"], "map:">;
+def map_file : P_priv<"map">;
 def show_timing : F<"time">;
 def summary : F<"summary">;
 
 //==============================================================================
 // The flags below do nothing. They are defined only for link.exe compatibility.
 //==============================================================================
 
-class QF<string name> : Joined<["/", "-", "/?", "-?"], name#":">;
-
 def ignoreidl : F<"ignoreidl">;
 def nologo : F<"nologo">;
 def throwingnew : F<"throwingnew">;
 def editandcontinue : F<"editandcontinue">;
 def fastfail : F<"fastfail">;
 
-def delay : QF<"delay">;
-def errorreport : QF<"errorreport">;
-def idlout : QF<"idlout">;
-def maxilksize : QF<"maxilksize">;
-def tlbid : QF<"tlbid">;
-def tlbout : QF<"tlbout">;
-def verbose_all : QF<"verbose">;
-def guardsym : QF<"guardsym">;
+def delay : P_priv<"delay">;
+def errorreport : P_priv<"errorreport">;
+def idlout : P_priv<"idlout">;
+def maxilksize : P_priv<"maxilksize">;
+def tlbid : P_priv<"tlbid">;
+def tlbout : P_priv<"tlbout">;
+def verbose_all : P_priv<"verbose">;
+def guardsym : P_priv<"guardsym">;