+ emit an error message if the ihxutil is not found when compiling an ZX Spectrum executable with the internal linker

+ emit a 'tried' message (fpc -vt) when using ihxutil for ZX Spectrum

compiler/systems/t_zxspectrum.pas

@@ -441,8 +441,13 @@ function TInternalLinkerZXSpectrum.postprocessexecutable(const fn: string): bool
 
     if Found then
       begin
+        Message1(exec_t_using_util,FoundBin);
         exitcode:=RequotedExecuteProcess(foundbin,' '+fn);
         result:=exitcode<>0;
+      end
+    else
+      begin
+        Message1(exec_e_util_not_found,utilexe);
       end;
   end;