* some warnings fixed

compiler/pdecl.pas

@@ -803,6 +803,7 @@ implementation
                     (oo_is_forward in tobjectdef(ttypesym(sym).typedef).objectoptions) then
                   begin
                     wasforward:=true;
+                    objecttype:=odt_none;
                     case token of
                       _CLASS :
                         objecttype:=default_class_type;

compiler/pexpr.pas

@@ -2383,6 +2383,7 @@ implementation
 
                if (p1.nodetype=stringconstn) and (token=_ID) then
                  begin
+                   strdef:=nil;
                    { the def of a string const is an array }
                    case tstringconstnode(p1).cst_type of
                      cst_conststring:

compiler/symsym.pas

@@ -548,6 +548,7 @@ implementation
 
     function same_constvalue(consttyp:tconsttyp;const value1,value2:tconstvalue):boolean;
       begin
+        result:=false;
         case consttyp of
           constnone,
           constnil: