Fix GetEyeTraceNoCursor caching (#1645)

* Fix GetEyeTraceNoCursor caching

Fixes Facepunch/garrysmod-issues#4430.

Also
- Use FrameNumber instead of CurTime for caching so that it doesn't clash with prediction
- Added skipcache arg to both GetEyeTrace and GetEyeTraceNoCursor for skipping the clientside cache
- Check if the PlayerTrace/PlayerAimTrace vars are tables before returning them in-case they're modified by other addons accidentally

* Fix styling

* Remove skipcache arg

garrysmod/gamemodes/base/gamemode/obj_player_extend.lua

@@ -173,45 +173,41 @@ end
 	Player Eye Trace
 -----------------------------------------------------------]]
 function meta:GetEyeTrace()
-
 	if ( CLIENT ) then
-		local curtime = CurTime()
+		local framenum = FrameNumber()
 
 		-- Cache the trace results for the current frame, unless we're serverside
 		-- in which case it wouldn't play well with lag compensation at all
-		if ( self.LastPlayerTrace == curtime ) then
+		if ( self.LastPlayerTrace == framenum ) then
 			return self.PlayerTrace
 		end
 
-		self.LastPlayerTrace = curtime
+		self.LastPlayerTrace = framenum
 	end
 
 	local tr = util.TraceLine( util.GetPlayerTrace( self ) )
 	self.PlayerTrace = tr
 
 	return tr
-
 end
 
 --[[---------------------------------------------------------
 	GetEyeTraceIgnoreCursor
 	Like GetEyeTrace but doesn't use the cursor aim vector..
 -----------------------------------------------------------]]
 function meta:GetEyeTraceNoCursor()
-
 	if ( CLIENT ) then
-		local curtime = CurTime()
+		local framenum = FrameNumber()
 
-		if ( self.LastPlayerAimTrace == curtime ) then
+		if ( self.LastPlayerAimTrace == framenum ) then
 			return self.PlayerAimTrace
 		end
 
-		self.LastPlayertAimTrace = curtime
+		self.LastPlayerAimTrace = framenum
 	end
 
 	local tr = util.TraceLine( util.GetPlayerTrace( self, self:EyeAngles():Forward() ) )
 	self.PlayerAimTrace = tr
 
 	return tr
-
 end